What call indicates an officer requires help with units responding from different agencies?

The correct answer highlights a scenario in which an officer is seeking assistance, specifically calling for any available units to respond, regardless of their agency affiliation. This call signals to all units in the vicinity that they should be on alert and ready to provide support to the officer in need.

In law enforcement, this type of communication is vital when an officer faces a situation that exceeds their capacity to manage alone, such as potentially dangerous confrontations or emergency situations. By requesting "any units respond," the officer opens the door for immediate assistance from nearby agencies, fostering a collaborative response in critical times.

The other options pertain to specific types of requests that may not convey the immediacy or broad inclusion necessary for various units to assist. For instance, asking for immediate backup focuses on those closest at hand, while calling for a SWAT team or air support denotes specific tactical needs that might not draw on a wide range of responding agencies.