The best answer is B. It provides a timeline and schedule for deploying new releases into production.
ISACA release and change guidance explains that successful deployment requires scrutiny over change and release, including scheduling, coordination among parties, and validation before implementation. That aligns directly with the role of a release plan: organizing when and how releases move into production.
Option A is more closely related to configuration management. Option C is too narrow because release plans cover much more than database integration. Option D is more closely associated with change evaluation and impact assessment before approval. The release plan's main function is the coordinated timeline and schedule for production rollout.
References (Official ISACA):
ISACA Journal, Implementing Emerging Technologies
ISACA Journal, Speeding Up Software Delivery With Effective Change Management