Explanation:

The Business Requirement
UC wants to detect any discount applied on options in bundles. If any option is discounted, mark a custom field on the Quote (Is_Discounted__c) = TRUE.

The logic to achieve this:
1. Identify only the options inside bundles.
2. Check whether any of those lines have a discount greater than 0.

So, the price rule should target the Quote object, use a Summary Variable to scan Quote Lines, and apply Price Conditions on the summary variable to detect a discount.

✅ B. A Price Condition where the Tested Variable must equal 0. The Summary Variable should have these values: Aggregate Function — Max Target Object — Quote Line Aggregate Field — SBQQ__Discount__c

This is correct.

You need a Summary Variable on Discount across Quote Lines. You’d set it up as:
- Aggregate Function = MAX
- Aggregate Field = SBQQ__Discount__c
- Target Object = Quote Line

If any line has a discount > 0, the MAX value is greater than zero. In the Price Condition, you’d check:
Tested Variable = Summary Variable
Operator = Greater Than
Filter Type = Value
Filter Value = 0
This detects if any quote line is discounted.

✅ D. A Price Condition with: Object — Quote Line Field — SBQQ__ProductOption__c Operator — Not Equals Filter Type — Value Filter Value — (Null)
This is also correct.

SBQQ__ProductOption__c is populated on option lines (child products in bundles). If SBQQ__ProductOption__c is NOT null, it’s an option. So, this condition limits the summary variable only to options. This ensures the summary variable considers only bundle options, not the parent bundles themselves.

Why not the other options?

A. A Price Condition Tested Formula of SBQQ__RequiredBy__r.SBQQ__Bundled__c = TRUE
This is incorrect. The RequiredBy relationship points to the parent product option. However, SBQQ__Bundled__c doesn’t exist in that way. This condition would not reliably filter just option lines. Instead, SBQQ__ProductOption__c is the reliable indicator for identifying options.

C. A Price Condition with: Object = Quote Line Field = SBQQ__Discount__c Operator = Greater Than Filter Type = Value Filter Value = 0
This is incorrect on its own. This condition only tests individual quote lines for discount. It’s not appropriate for a Price Rule on the Quote level. Without summarizing across lines, it cannot flag the Quote itself if any option is discounted.

Hence, B and D are the correct combination.

✅ Recommended Setup

You’d configure:
- Summary Variable:
- Aggregate Function = MAX
- Aggregate Field = SBQQ__Discount__c
- Target Object = Quote Line
- Filter = SBQQ__ProductOption__c ≠ NULL

- Price Condition on Summary Variable:
- Tested Variable = [Summary Variable]
- Operator = Greater Than
- Filter Value = 0

- Price Action:
- Target = Quote.Is_Discounted__c
- Value = TRUE

That perfectly meets UC’s requirement.