Which code signifies that an ambulance is required?

The correct choice indicating that an ambulance is required is identified by the code 901-N. This code is specifically designated in many emergency response protocols to signal that the situation necessitates the response of an ambulance.

In contrast, other codes such as 901-T might refer to another type of incident or require a different level of response, while 902 codes are typically associated with different situations, like traffic collisions or other medical emergencies that do not automatically necessitate ambulance transport. Therefore, understanding the specific meanings assigned to each code is crucial for effective communication during emergency situations.