Why Have Genre Films Been Prevalent Since the Advent of Cinema

Why have genre films been prevalent since the advent of cinema?

A) They are the most challenging kind of movie to produce.
B) They are the cheapest kind of movie to produce.
C) They immediately possess a preestablished script in the form of the literary sources upon which they are always based.
D) They involve little to no creative input from the director.
E) They appeal to audiences' preference for predictability over novelty.