Answer: a smack is when someone does a slap but super hard. A slap is a light attack to the face that still hurts just not as bad.
Explanation:
using process of elimination you can eliminate condescending and pessimistic, and the passage doesn't really seem humorous either so your left with enthusiastic. The author seems to be happy and excited to share knowledge about how literature can make people feel, thus the best answer choice is probably enthusiastic
The past influences the present what has been lost can be regained.