Scenario Two Researchers Addressed the Generally Accepted Idea That Boxer Shorts

Scenario
Two researchers addressed the generally accepted idea that boxer shorts are better for male fertility than briefs because they lower testicular temperature. They begin by saying, "Although this idea is regarded as dogma by many in the lay community and the changing of underwear type is a therapy frequently recommended by medical practitioners, there is a paucity of data measuring scrotal temperature as a function of underwear type. ("Munkelwitz, Robert, and Gilbert, Bruce R. "Are boxer shorts really better? A critical analysis of the role of underwear type in male subfertility." The Journal of Urology, 160.4 (1998) : 1329-1333.)
-What hypothesis are these authors testing?

A) Boxer shorts allow the scrotal sac to be more exposed to outside temperature than briefs do.
B) Boxer shorts fit more loosely than briefs.
C) Boxer shorts allow the scrotal sac to have a lower temperature than briefs do.
D) Men with impaired fertility are more likely to wear briefs than boxers.