Answer:
a. Yakov playing his music loudiy does not do any harm if Charies is not home.
Explanation:
A command-and-control policy that forbids music to be played at high decibels in all periods of time might lead to an inefficient outcome because as the answer explains, if Yakov plays loud music when Charles is not home, Yakov is not harming anyone, and in fact, he could be benefiting someone: himself, either by relaxing if he listens to the music, or by becoming a better musician if he plays the music.
