What Evidence Do We Have That Newborn Infants Can Distinguish

What evidence do we have that newborn infants can distinguish between the sounds "ba" and "pa"?

A) They make both sounds in their own babbling.
B) Their heart rate increases when they hear "pa" but not when they hear "ba."
C) After habituating to "ba," they increase their sucking rate when they hear "pa."
D) They turn to the left when they hear "ba," and they turn to the right when they hear "pa."