In Montreal,Laura-Ann Petitto Has Done Some Important Research on Babbling

In Montreal,Laura-Ann Petitto has done some important research on babbling with normal and deaf babies.What has she found

A)  Deaf babies exhibited "manual babbling" with their hands in a manner similar to the verbal babbling of normal babies. 
B)  Deaf babies do not exhibit babbling with their hands. 
C)  Deaf babies exhibited "manual babbling" with their hands but their first signed words were not continuous with their babbling. 
D)  Deaf babies babble orally the same as normal babies.