DMARC (Domain-based Message Authentication, Reporting, and Conformance)helps organizations prevent email spoofing and phishing by enforcing policies based on SPF and DKIM. * Option B (DKIM - DomainKeys Identified Mail)verifies message integritybut does not enforce policies. * Option C (SPF - Sender Policy Framework)prevents spoofingbut is not as comprehensive as DMARC. * Option D (SMTP - Simple Mail Transfer Protocol)is just anemail delivery protocol, not a security control. Thus,A (DMARC) is the correct answer, asit combines SPF and DKIM to prevent spoofing and phishing attacks.