Acceptance criteria must be concrete, testable, and focused on observable system behavior. They define what the system must do to satisfy a requirement and help determine whether the requirement has been successfully implemented.

REQ 3.28 states: “The automated system records critical credit application data (CCAD) needed to support application screening.” From this, we infer that the system must persistently store this data after data entry.

Option A is the best match because it provides a specific, observable behavior (CCAD being stored in a MySQL database after a successful entry) that can be verified through acceptance testing. It’s a measurable outcome, aligned with the requirement's objective.

Other options are less suitable:

Option B introduces new behavior (displaying a message) not directly tied to the original requirement.

Option C is vague ("quick and reversible") and lacks measurable criteria.

Option D refers to usability guidelines, which is not directly relevant to the storage functionality stated in the requirement.

Exact Reference – ISTQB CTFL Acceptance Testing Syllabus (Section 1.3.2):

“Well-written acceptance criteria are unambiguous, testable, and focused on observable results.”