Which entity requires that organizations handling FCI or CUI be assessed to determine a required Level of cybersecurity maturity?

When assessing SI.L1-3.14.2: Provide protection from malicious code at appropriate locations within organizational information systems, evidence shows that all of the OSC's workstations and servers have antivirus software installed for malicious code protection. A centralized console for the antivirus software management is in place and records show that all devices have received the most updated antivirus patterns.
What is the BEST determination that the Lead Assessor should reach regarding the evidence?

A Lead Assessor is presenting an assessment kickoff and opening briefing. What topic MUST be included?

Regarding the Risk Assessment (RA) domain, what should an OSC periodically assess?

During the review of information that was published to a publicly accessible site, an OSC correctly identifies that part of the information posted should have been restricted. Which item did the OSC MOST LIKELY identify?