Confusing question on economics, Plzz help?

Question

The deadweight loss from an excise tax comes about because:

A) the number of transactions in the market is reduced.

B) some mutually beneficial transactions do not take place.

C) a quota rent exists.

D) of both A and B.

Answer 1

D

Answer 2

A

because the price will go up.

Answer 3

d.> both a& b men same. c is out of context.