Which of the Following Has Not Been Demonstrated by Research

Which of the following has not been demonstrated by research on mimicry?

A) Within a few days of birth, infants mimic the facial expressions of adults.
B) Various species of nonhuman animals demonstrate rudimentary forms of mimicry.
C) People often mimic the facial expressions of others, but never mimic their overt behaviors.
D) People sometimes mimic facial expressions of which they are not even consciously aware.