Which of the Following Best Describes Charles Darwin's Theory of the Origin

Which of the following best describes Charles Darwin's theory of the origin of facial expressions?

A) Initially random, small facial movements became useful communicative signals for organisms, much in the way sexual selection can result in bizarre traits becoming bigger, such as peacock feathers
B) Each mammalian species evolved its own unique set of expressions, essentially from ""scratch,"" because species have such different facial musculature
C) Facial expressions begain as functional behaviors that solved adaptive problems, and over time these functions became secondary to the communicative value of expressions
D) He noted that individual people and animals often express emotions is highly unique and inconsistent ways, leading him to conclude that associative learning is responsible for the formation of facial expressions
E) He did not believe that the actions involved in facial expressions were random, but were instead pieces of serviceable habits that took on a communicative function over the course of evolution. Facial musculature across mammals is surprisingly well preserved, and in fact Darwin sought to document homologous expressions across species (so B is incorrect)