Why Might Lower-Class Speakers Continue to Use Styles of Language

Why might lower-class speakers continue to use styles of language that are stigmatized?

A) Styles of speech serve as a marker for membership into a group.
B) They do not have the appropriate education to adopt upper-class patterns of language.
C) They have never been exposed to standardized language, and so do not know that their speech is non-standard.
D) Styles of speech are inherited, and cannot be changed by individuals.