Which investigation collects the greatest amount of evidence?

• A. NAC
• B. NACI
• C. PPR
• D. SSBI

Answer: (D)

In background investigations, the depth of evidence gathered varies by type. The Single Scope Background Investigation is the most comprehensive, designed to build a complete picture of an individual. It employs extensive personal interviews with the applicant, references, and former employers or colleagues, and it verifies a wide range of information—education, employment history, residential history, finances, foreign contacts, and more. It also relies on corroboration from multiple sources and deeper record checks, going beyond what automated databases alone provide. Because it uses many sources, covers a longer time span, and integrates contextual information, it yields the greatest amount of evidence to support a suitability decision.