The Deadweight Loss Due to a ________ Is Always Smaller

The deadweight loss due to a ________ is always smaller than the deadweight loss due to a ________.

A) tax on each unit sold; tax on each unit bought
B) per unit tax on each unit sold; per unit tax on each unit bought
C) tax on each unit sold; lump-sum tax
D) lump-sum tax; tax on each unit bought