Suppose Darby Values a Certain Smart Phone at $400

Suppose Darby values a certain smart phone at $400. Jake values the same smart phone at $300. The pre-tax price of this smart phone is $250. The government imposes a tax of $75 on each smart phone, and the price rises to $325. The deadweight loss from the tax is

A) $150.
B) $50.
C) $0.
D) $100.