Why Did the Western Genre Decline in Popularity from the 1960s

Why did the Western genre decline in popularity from the 1960s until the mid-2000s?

A) because John Wayne's aging and eventual death robbed America of its greatest Western screen hero
B) because the increasing use of photographic color diminished the appeal of a genre inextricably associated with black-and-white
C) because the genre was seen to be out-of-touch with audiences who had new ideas about moral absolutes, Manifest Destiny, and the role of minorities in settling the West
D) because audiences demanded movies in which homosexuals were portrayed as flawless heroes
E) because the Western combined generic elements with those of the melodrama and romance