For One Group of Pigeons, a Black Vertical Bar on a White

Multiple Choice

For one group of pigeons, a black vertical bar on a white key light served as the S+ and the blank key light the S-. For another, the bar served as the S- and the blank key light the S+.When the bar was rotated toward the horizontal, the first group decreased pecking, and the second increased pecking.This demonstrates that

A) the response required influences discrimination training.
B) excitatory and inhibitory conditioning can occur in discrimination training.
C) discrimination training results in either excitatory or inhibitory conditioning, but not both.
D) overshadowing can influence discrimination training.