Condition and Validator are correct.

A Condition is applied to a workflow transition to prevent the transition action from appearing or being available unless the user meets the specified criteria such as membership in the InfoSec group. This stops users from even seeing or attempting the transition when they are not authorized.

A Validator runs when a transition is executed and enforces rules at runtime by rejecting the transition if the user does not meet the required checks. Using a validator ensures that even if the transition is triggered by an API or an unexpected route the membership requirement is still enforced.

Permission Scheme is incorrect because permission schemes control broad project level permissions like who can browse or edit issues and they do not restrict individual workflow transitions.

Issue Security Level is incorrect because issue security controls who can view an issue and it does not control who is allowed to move issues through workflow statuses.

Post Function is incorrect because post functions perform actions after a transition has completed and they cannot prevent a transition from occurring or validate the user before the transition runs.

Full AWS Practitioner Certification Question