What Is the Legal Consequence of a Trademark Becoming a Generic

What is the legal consequence of a trademark becoming a generic term?

A) No one can use the term in a name for that type of product.
B) Every seller must use the term to describe that type of product.
C) The fair use doctrine would not apply.
D) The holder of the trademark for the term that has become generic cannot prevent others from using the generic term.
E) There is no legal consequence.