Salesforce Connect

Explanation:

Salesforce Connect allows users to access external data from other Salesforce orgs or external systems through External Objects. This feature is ideal for scenarios where data must be available across multiple Salesforce orgs without physically replicating data between them. In this scenario, Northern Trail Outfitters needs users to have read-only access across multiple regional orgs. Salesforce Connect achieves exactly this, providing real-time, read-only visibility into external data residing in other Salesforce orgs. Salesforce-to-Salesforce (option B) copies data rather than providing real-time external access. Federated Search (option C) provides unified search but not direct record-level access. External APIs (option D) require more complex integration and don't inherently provide seamless read-only data views. Salesforce Connect offers the simplest, most effective way to meet this requirement efficiently.