Tom Yells at His Parrot Whenever It Squawks Because the Squawking

Multiple Choice

Tom yells at his parrot whenever it squawks because the squawking bothers the neighbors in the next apartment. Why is this procedure less than ideal?

A) The parrot could become very passive.
B) The parrot might still squawk when Tom is not home.
C) The parrot might become fearful of Tom.
D) All of these are correct.