Exam AI-500 Topic 1 Question 19 Discussion

The fastest safe rollback is to route the stable endpoint back to the previous known-good immutable agent version. Current Foundry lifecycle guidance supports versioned agents and endpoint/version selection so production traffic can be redirected without rebuilding the agent from scratch. Deleting the newly published version is a destructive cleanup action and is not the preferred rollback mechanism because it removes an artifact that may be needed for diagnosis. Creating a new agent changes the lifecycle identity and takes longer, while a complete redeployment is unnecessary if the earlier version already exists. Option C is therefore correct when interpreted as changing the endpoint ' s active-version or version-selector configuration to the previous version while keeping the endpoint URL stable. From a security and governance perspective, the control should be enforced at the narrowest platform boundary that can deterministically block or constrain the action. Relying only on prompt text is weaker because the model can still be induced to behave unexpectedly.
Official Microsoft reference: Microsoft Foundry agents - development lifecycle and versioning