Infants Around Age 6 Months Babble

Infants around age 6 months babble. To what extent is their babbling influenced by what they hear?

A) The more the infant hears, the less it babbles.
B) From birth onward, the amount of babbling is directly proportional to how much the parents talk to the infant.
C) At first infants copy the sounds they hear; later they begin to invent new sounds of their own.
D) At first, what infants hear makes no difference; later they begin to copy the sounds they hear.