In One Study, a Researcher Monitored Newborns' Responses to the Sound

In one study, a researcher monitored newborns' responses to the sound sequence "ba-ba-ba-ba-ba..." until their response habituated, and then substituted the sound "pa." What happened to the infants' responses, and what conclusion follows?

A) Their responses decreased. Conclusion: They interpret the change as threatening.
B) Their responses stayed the same. Conclusion: They cannot tell the difference.
C) Their responses increased. Conclusion: They can tell the difference between the sounds.
D) Their responses increased. Conclusion: They prefer the sound "pa" to "ba."