Figure 4.4 represents the market for gasoline in a small nation. The free trade world price of gasoline is $3.50. Suppose this small nation imposes a tariff on gasoline of $.50 per gallon. The change in consumer surplus would be
选项：

A: area a + b
B: area a
C: area a + b + c + d + e
D: area a + b + f + g + h