ATC Services COMMS
Many of the ATCATC —Air Traffic Control services are self-evident, but there are one or two traps. Firstly, aerodrome control is TOWER, not control. If the question has the word "arrivals" or "departure" in it, that is probably the right answer - if it simply says "approach control", the callsign is APPROACH. At the more niche end, there are two callsigns DELIVERY for obtaining clearance and DISPATCH for contacting the company, but "clearance" and "company" are not callsigns themselves.