What Role Does an Infant's Attention to Facial Expressions Play

What role does an infant's attention to facial expressions play in his or her understanding of language?

A) Facial expressions are irrelevant to understanding spoken language.
B) Babies do not pay attention to facial expressions of speakers.
C) When there is a mismatch between facial expression and word meaning, babies will rely on the word meaning.
D) A baby can tell whether a speaker is using the baby's native language by looking at the speaker's mouth movements without any sound.