Final answer:
Among the presented scenarios, Sam Lee's request to discontinue his Personnel Security Clearance process must be reported to the DCSA as it impacts national security and clearance processes.
Step-by-step explanation:
Within the context of security and potential risks to national security, it is important to know which scenarios must be reported to the Defense Counterintelligence and Security Agency (DCSA). Among the scenarios presented, scenario B must be reported to DCSA: Sam Lee, who is being processed for a Personnel Security Clearance (PCL), has asked to discontinue the clearance process.
This is because a change in status or an individual's decision regarding their security clearance can have implications for national security and organizational operations. The other scenarios involving Sharon Crumb's employment, Leila Broom's house purchase, and upgrading a building's alarm system do not require reporting to DCSA, as they do not directly impact security clearance processes.