Explanation: The various phases of NIST SP 800-37 C&A are as follows: Phase 1: Initiation- This phase includes preparation, notification and resource identification. It performs the security plan analysis, update, and acceptance. Phase 2: Security Certification- The Security certification phase evaluates the controls and documentation. Phase 3: Security Accreditation- The security accreditation phase examines the residual risk for acceptability, and prepares the final security accreditation package. Phase 4: Continuous Monitoring-This phase monitors the configuration management and control, ongoing security control verification, and status reporting and documentation.