The DNI issued several _ and which provide security policy for the protection of national intelligence as well as the personnel security requirements for access to SCI, and physical and technical security requirements for SCIFs.

a. Directives, Regulations
b. Policies, Guidelines
c. Mandates, Procedures
d. Laws, Standards

The Director of National Intelligence issues policies and guidelines that shape the security measures of national intelligence operations, including access to SCI and the security of SCIFs, which are essential for maintaining national security posture.

Explanation:

The Director of National Intelligence (DNI) was established to increase the efficiency and effectiveness of the U.S. intelligence community by serving as the primary advisor to the President and overseeing national intelligence operations. Following intelligence failures, the DNI was charged with the management of an extensive budget and the coordination of various intelligence agencies, including the CIA, which now reports to the DNI. The directives and policies issued by the DNI provide critical guidelines for the security and protection of intelligence operations.

In the context provided, the DNI issued several policies and guidelines which dictate the security policy for national intelligence, including personnel security requirements for accessing Sensitive Compartmented Information (SCI), and physical and technical security requirements for Sensitive Compartmented Information Facilities (SCIFs). Policies and guidelines help to clarify and interpret regulations, though they do not carry the force of law themselves. Instead, they provide essential direction and principles for conducting intelligence activities.