Refer to the Figure Below to Answer the Following Questions

Refer to the figure below to answer the following questions.

The figure shows the market for shirts in Canada, where D is the domestic demand curve and S is the domestic supply curve.The world price is $20 per shirt.Canada imposes a tariff on imported shirts of $4 per shirt.
Figure 31.2.1
-Refer to Figure 31.2.1,the Canadian government's revenue from the tariff is ________.

A) $64 million
B) $32 million
C) $128 million
D) $48 million
E) $480 million