A: In the U.S., which gender watches, on television, more athletic events (sports)?
B: Survey. Seems to be the most logical route. It could give hard evidence as to the answer to this question.
C: Hire a polling firm to take a poll of an equal, substantial amount of males and females, randomly chosen, across a wide geographical area. Anylaze the data with appropriate scientific techniques.
D: Possible issues of male/female chauvinism could arise. I would write as clear, direct to the point questions as possible. I would make sure that the polling was well supervised by professional Sociologists.