A multi-agent repository retired legacy-review-agent and introduced secure-review-agent. A pull request opened after the retirement still shows a required check named legacy-review-agent / review-gate stuck in pending. The team checks the workflow and branch protection evidence. Which option best identifies the root cause? Select one answer.

The correct answer is "The required check references the retired agent." The ruleset audit note explicitly states that "required checks not changed" when legacy-review-agent was retired and secure-review-agent was introduced. This means the branch protection rule still requires the legacy-review-agent / review-gate check, even though the corresponding workflow (legacy-review-gate.yml) no longer exists in the repository. Since no workflow run can be found for legacy-review-gate.yml, this required check remains in a pending state indefinitely, blocking the pull request. "The secure review workflow failed silently" is incorrect because the secure-review-gate.yml workflow run shows "success." "The agent profile still exposes write tools" is irrelevant to a stuck pending check; it relates to agent security, not workflow execution. "The pull request skipped path-filtered jobs" is incorrect because there's no indication of path filtering, and the core issue is a missing required check, not a skipped job.