This is shown throughout the whole story. The author describes bad events that usually happen to the other boys or they reform after realizing they were wrong, but then the author goes on to explain how that’s not the case for this story.
A: terribly: modifies old, an adjective B: very smart: very modifies smart, an adjective C; extremely modifies "slow", an adjective again D: quickly modifies "hid" a verb - this is the correct answer!
