June's cat runs to the kitchen at the sound of the electric can opener, but not when a blender is used. June's cat is demonstrating stimulus:

discrimination.

Explanation:

Stimulus discrimination: In psychology, the term "stimulus discrimination" is described as a stimulus that consists of the capability to differentiate between one stimulus and some other stimulus similar to the previous one. Therefore, it indicates that an organism responds only to the actual stimulus but not to some other similar stimulus. Stimulus discrimination is being used in both types of conditioning i.e., operant and classical conditioning.

In the question above, the given statement represents that June's cat is demonstrating stimulus discrimination.

the answer to your question is,

d. when a child was born.

-mabel < 3