​The following is NOT an example of a potential monitoring solution to moral hazard

A) ​blocking social network sites on company computers
B) rejecting a job candidate that fails to show up at the allotted interview time
C) GPS tracking devices in repair trucks
D) ​listening in on call center conversations

Rejecting a job candidate that fails to show up at the allotted interview time is not a potential monitoring solution to moral hazard. This is a measure to enforce punctuality and professionalism, but it does not address the issue of moral hazard, which refers to the tendency of individuals to take risks or engage in harmful behavior when they are protected from the consequences of their actions. The other choices (blocking social network sites, GPS tracking, and listening in on call center conversations) are all examples of monitoring solutions that can help deter or detect moral hazard in different contexts.