In which situation is backup not required to be called?

Backup is not required to be called during supervision because this situation typically involves monitoring inmates in a controlled environment where they are not displaying any signs of danger or hostility. When an officer is supervising inmates, they are often in a position of oversight rather than confrontation. In such scenarios, the officer is able to manage interactions with inmates effectively and assess the environment for any potential issues. The presence of backup may not be necessary unless a situation escalates beyond normal supervision, allowing officers to maintain a routine operation and ensure safety without the immediate support of other personnel.

In contrast, the other options involve situations that are inherently more volatile or dangerous, where the risk of escalation to violence or harm is higher, necessitating backup to ensure the safety of both the officer and inmates.