What Was NOT a Criticism of Introspection as a Technique

What was NOT a criticism of introspection as a technique?

A) It was an unreliable method since different participants often provided different reports about the same stimulus.
B) Introspection revealed unconscious conflicts rather than conscious experiences.
C) Introspection could not be used to study children or animals.
D) A number of topics, including learning, development, and mental disorders, could not be studied using this technique.