Explanation:

Why This Is the Recommended Approach
The reported problem is poor Visualforce page performance in production. Accurate diagnosis almost always requires the sandbox to replicate the exact symptoms seen in production, which means it must have:

Real production data volume (millions of records that cause SOQL timeouts, slow queries, unselective filters, etc.)
The same indexes, skinny tables, and query execution plans that exist in production
Production-like sharing rules, role hierarchy, and record-level sharing that affect query performance
The exact same Visualforce + Apex code (which is already guaranteed by source control, but irrelevant if data is missing)

Only a Full Sandbox meets these requirements because it is an exact byte-for-byte copy of production (metadata + all data). Partial Copy sandboxes cap at ~10K records per object and ~5 GB total, Developer/Pro have even less — none of them can reproduce real-world performance bottlenecks.
Salesforce explicitly states that performance and load testing must be done in a Full sandbox or a scaled-down Full sandbox for any credibility.

Why the Other Options Are Incorrect
Option A – Partial Copy Sandbox
Contains only a tiny data sample and templates. Impossible to reproduce volume-related performance issues (e.g., full-table scans, governor limit breaches, slow list views).

Option B – Developer Sandbox
Only 200 MB of data, no sample records at all by default. Completely useless for performance diagnostics.

Option D – Developer Pro Sandbox
10 GB limit, still no real production data volume. Still cannot replicate the issue.

References
Trailhead → “Sandbox Types and When to Use Them” → Full sandbox is required for performance testing, UAT with real data volumes, and load testing.
Salesforce Help → “Sandbox Environment Considerations” → “Only Full sandboxes contain enough data to test performance and scalability.”
Salesforce Performance Testing Guide → “Use a Full sandbox (or a Full sandbox with data obfuscation) for any performance investigation.”
Architect Journey → Data Architecture & Management → “Diagnose query or page performance → Full sandbox only”

Summary
Real Visualforce performance problems are almost always data-volume or sharing-related → only a Full Sandbox can reliably reproduce and diagnose them.
Correct answer: C.

Explanation
: The benefits of managing change with Packaged Development are:

Versioning to help with change management, as it allows the developers to track the changes made to the metadata and roll back to previous versions if needed. Making the release cycle more efficient and agile, as it enables the developers to deploy smaller and more frequent updates to the orgs, reducing the risk of errors and conflicts.

Modular development process with specification of dependencies among packages, as it allows the developers to break down the metadata into logical units that can be reused and updated independently, while ensuring that the dependencies are resolved correctly. Managing the number of sandboxes needed to successfully deploy is not a benefit of Packaged Development, as it is more related to the sandbox strategy and the development model. Clearly dividing developers and testers is also not a benefit of Packaged Development, as it is more related to the team structure and the testing strategy.

Explanation:
Identifying the relevant data and verifying the data integrity can help ensure the quality and accuracy of the migrated data. Using a full sandbox and performing test runs with real data can help validate the migration process and identify any issues or risks.

Explanation:

Why B and C are the correct choices
B. Program Team
Correct – The Program Team (program managers, release managers, architects, DevOps leads, technical leads from each workstream) are the core operational members of any Salesforce Center of Excellence. They define standards, enforce governance, own tools & processes, run training, and drive continuous improvement. Without the program/delivery team inside the COE, it has no ability to execute or enforce anything.

C. Executive Sponsors
Correct – Executive Sponsors (VP/Director/C-level from Sales Ops, RevOps, IT, Digital, etc.) are mandatory members of a successful COE. They provide:
- Strategic direction and priorities
- Funding and resource allocation
- Authority to enforce standards across the organization
- Escalation and conflict-resolution power when teams resist governance

Salesforce and every major analyst firm (Gartner, Forrester) explicitly state that a CoE without active executive sponsorship fails within the first year.

Why the other two options are incorrect
A. Call Center Agents
Wrong – End-users such as call-center agents are consumers of the platform, not members of a Center of Excellence. They provide valuable feedback in steering committees or user-advisory groups, but they do not define architecture standards, release processes, or DevOps tooling.

D. Inside Sales Users
Wrong – Same as A. Everyday sales reps are critical stakeholders and should be consulted, but they do not belong inside the COE itself.

References
Salesforce Well-Architected Framework → “Center of Excellence”
“A successful CoE must include Executive Sponsors for authority and the Program/Delivery Team for execution.”

Trailhead → “Implement a Salesforce Center of Excellence”
Explicitly lists Executive Sponsors + Program/Technical Team as required members.

Salesforce COE Playbook (public PDF) → Membership matrix shows Executive Sponsors and Program Team as the two mandatory groups.

Bonus Tips
Memorize: Starting a CoE → always Executive Sponsors + Program Team (C + B).
End-users (agents, sales reps, etc.) are never part of the core CoE — they sit on advisory or steering committees instead.
This exact question (or very close variant) has appeared multiple times on the real Development Lifecycle and Deployment Architect exam.

Explanation:
This is the correct answer because Salesforce prohibits stress testing against production because it is a shared environment that hosts multiple customers and tenants. Stress testing against production may affect the performance and availability of the Salesforce service for other customers and violate the terms of service. Stress testing should be done in a sandbox or a developer edition org that is isolated from production.