A team wants to deploy a new feature to production for internal users only and...

Feature flags are the most effective way to control feature exposure to specific users, such as internal testers, while enabling fast rollback without redeployment. Option B is correct because feature flags allow teams to decouple deployment from release, giving precise runtime control over feature availability. This means that once the code is deployed, the team can toggle the feature on or off for different cohorts (e.g., internal users) dynamically.

Option A (blue/green deployment) controls traffic between two environments but does not provide user-level granularity. Option C (canary deployments) gradually expose changes but focus on random subsets of users rather than targeted groups such as internal employees. Option D requires redeployment or rollback, which introduces risk and slows down incident response.

Feature flags are widely recognized in platform engineering as a core continuous delivery practice that improves safety, accelerates experimentation, and enhances resilience by enabling immediate mitigation of issues.