When is it permissible to pass a school bus that has its stop arm extended?

Passing a school bus that has its stop arm extended is against the law at all times. The extended stop arm indicates that children are either boarding or exiting the bus, creating a situation where their safety could be compromised if a vehicle were to pass. Laws are designed to protect children in these scenarios, as they may unexpectedly step into the roadway without looking for oncoming traffic.

The other choices suggest scenarios where passing might be considered, but they do not take into account the critical safety measures necessary when it comes to school buses. Thus, the clear and lawful answer is that it is never permissible to pass a school bus with its stop arm extended, reinforcing the importance of ensuring the safety of young pedestrians.