Well my fave are actually A-C but I wear a certain type depending on the time of year.
I prefer wearing briefs for winter so everything is as close and warm as possible.
I prefer boxer-briefs for spring and fall so things stay warm but I can catch ay good draft and keep cool
And I prefer boxers for summer so everything can be cool and breezy and nothing gets to hot
As far as swim suit goes I usually stick with option C but I do wear option B sometimes