The Best Evidence That There Is a Critical Period for Language

Multiple Choice

The best evidence that there is a critical period for language mastery is the fact that

A) infants babble in sounds that occur in their parents' native language.
B) toddlers maintain a capacity to discriminate language sounds they have never heard.
C) people most easily master the grammar of a second language during childhood.
D) preschoolers typically fail to use proper syntax.