When a sales user is amending assets, the amendment quote does not have a contract...

Comprehensive and Detailed Explanation From Exact Extract:

When beginning an amendment:

From the Revenue Cloud Amendment Guide:

“If an amendment is initiated from the Account, Salesforce cannot automatically determine which Contract to use, so the Amendment Quote is created without a Contract reference.”

“To automatically associate the Contract, amendments must be initiated from the Contract record or the Contract’s Asset list.”

Option A is not related to contract population rules.

Option C is the scenario where the Contract is automatically populated, not where it is missing.