Which investigation includes citizenship checks and spouse/cohabitant NACs as required?

• A. NAC
• B. NACI
• C. SSBI
• D. PPR

Answer: (C)

The level of background investigation determines what checks are performed. The Single Scope Background Investigation is the most thorough DoD background check used for higher-level clearances, and it explicitly includes verifying the applicant’s citizenship and performing NAC inquiries on the applicant’s spouse or cohabitant. This combination helps uncover any foreign influence risks tied to both the individual and their household, which is why this option fits the requirement. The other investigations are more limited in scope: a National Agency Check focuses on federal records, a National Agency Check with Inquiries adds some questions but not the same depth, and the remaining option isn’t a standard full-scope background investigation for this purpose.