Which Response Would Show That a Pigeon Understands the Principle

Multiple Choice

Which response would show that a pigeon understands the principle of "sameness" within a particular category?

A) The pigeon will peck repeatedly every time it sees the identical picture.
B) The pigeon will peck in response to a leaf-covered tree or a bare tree.
C) The pigeon will discriminate between physically similar stimuli.
D) All of the above answers are correct.