Nisbett and Wilson Examined People's Consciousness About Their Higher Mental

Nisbett and Wilson examined people's consciousness about their higher mental processes. According to their research,

A) we can usually provide valid introspections about conscious processes.
B) it is impossible to have access to our thought processes.
C) we are often unable to introspect accurately about our thought processes.
D) we can introspect accurately about memory and higher mental processes, but not about perception.