There are steps involved to implement a test plan during A$3.$ What does "Showstopper Identification" indicate?

Question $3$ options:

It defines the external resources and required tools to ensure the SW conforms the specified requirements.

It defines the user group helps testers identify acceptable levels of failures and risks.

It defines the the scenarios should be in the use case, If not, a revisit to the requirements might be necessary.

It defines the level of details for test plans that would be executed during testing.