A stimulus involves a previously neutral stimulus that eventually elicits the conditioned response after being associated with the unconditioned stimulus.

A conditioned stimulus involves a previously neutral stimulus that eventually elicits the conditioned response after being associated with the unconditioned stimulus.

Explanation:

A conditioned stimulus is defined as that neutral stimulus that after its more or less repeated association with an unconditioned stimulus, starts to cause a response (conditioned response) similar to that caused by the unconditioned stimulus, that is, a conditioned stimulus is all that internal or external stimulus that initially causes no reaction in an organism. However, through a classic conditioning process, it gets to create a response.

i believe it is c: genes for body color and wing size are inherited separately from each parent.