Answer:
A. Are listening
Explanation:
Process of elimination.
B: Saying "we listen to the radio" just means that we occasionally/often/routinely listen to it. It doesn't mean that we are actively doing it.
C: "listens" is conjugated for "he listens" or "she listens", not "we listens".
A: there are no issues with this. this must be the answer.
Pro tip: If a verb is in the form of "am/are/is ____ing" that usually means that it's happening right now.