Firm Evidence That 4-Month Olds Can Detect a Correspondence Between

Firm evidence that 4-month olds can detect a correspondence between sounds and sights comes from reports of their increased attention

A) to films with mismatched, as opposed to matched, soundtracks.
B) to mother's face when accompanied by the voice of a stranger than when it is accompanied by her own voice.
C) to a speaker whose word (one repeated several times beforehand) was heard on a soundtrack.
D) All of the alternatives are correct.