The correct option is Verification.

Verification refers to the set of activities that confirm a product has been built according to its documented design and security requirements. It typically includes tests, inspections, and reviews that check conformance to specifications so executing tests to confirm compliance is a verification activity.

Security testing is focused specifically on finding security vulnerabilities and evaluating resistance to attack and it does not necessarily cover general conformance to all documented design requirements.

Assessment is a broader term that can mean an audit or evaluation of various aspects of a system and it does not specifically denote the execution of tests to prove compliance with detailed specifications.

Validation is about confirming the system meets the needs and intended use of stakeholders and end users and it is more concerned with "building the right system" rather than "building the system right" which is what verification covers.

Full AWS Practitioner Certification Question