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) There was too great an emphasis on the physiological mechanisms that made the technique work so effectively.
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.