Abackdooris a deliberate vulnerability inserted into the code, often allowing unauthorized access.

Source code review (Option D)is the best way to detect malicious code before it is deployed to production.

SDLC training (Option A)is helpful but does not directly prevent the insertion of backdoors.

Dynamic analysis (Option B)detects vulnerabilities at runtime but may not always identify backdoors in code.

Debugging (Option C)is useful for troubleshooting but does not address security vulnerabilities.

???? Reference:CompTIA CySA+ CS0-003 Official Study Guide, Secure Software Development Practices.