单项选择题

If a country places a 10 percent tariff on imports of shoes and a 5 percent tariff on imports of all materials required for making shoes, the effective rate of protection provided for the shoemaking industry will be
A、higher than 10 percent.
B、10 percent.
C、5 percent.
D、between 10 percent and 5 percent, depending on the importance of imported materials.

A.
B.
C.