What does the suffix "/T" indicate about an aircraft's transponder?

The suffix "/T" indicates that the aircraft is equipped with a transponder, but it does not specify that it is equipped with Mode C. Mode C is a specific transponder mode that provides altitude information, whereas the "/T" suffix designates a transponder presence without the additional altitude-reporting capability. This means the aircraft meets the basic transponder requirements, but it lacks the functionality for reporting altitude data that is characteristic of Mode C.

The other options either misrepresent the abilities of the transponder or incorrectly classify its functionality, such as indicating that it has no transponder or suggesting a full capability with Mode C or DME, which the "/T" suffix does not imply. Therefore, the correct interpretation leads to the conclusion that the aircraft has a transponder but not with Mode C, aligning with the identification provided by the suffix.