Whenever Baby Colin Cries,his Mother Picks Him Up

Multiple Choice

Whenever baby Colin cries,his mother picks him up.This stops Colin from crying.In turn, this makes Colin's mother pick him up more often.In this example,his mother picking him up
Serves as a ________ reinforcer for Colin.Colin stopping crying is a ________ reinforcer
For the mother.

A) negative;negative
B) negative;positive
C) positive;negative
D) positive;positive