The Phase 4 of DITSCAP C&A is known as Post Accreditation. This phase starts after the system has been accredited in Phase 3. What are the process activities of this phase? Each correct answer represents a complete solution. Choose all that apply.

A. Maintenance of the SSAA
B. Compliance validation
C. Change management
D. System operations
E. Security operations
F. Continue to review and refine the SSAA