According to the Idea of "Telling More Than We Can

According to the idea of "telling more than we can know" by Nisbett,Ross,and Wilson,one reason that introspection is sometimes not an accurate way to learn about oneself is

A) people have to be extremely self-aware to learn anything about themselves.
B) people must rely on controlled processes to effectively introspect.
C) mental processes are not observable,and therefore do not actually exist.
D) many of our mental processes occur outside our awareness.