Refer to the diagram, where S d and D d are the domestic supply and demand for a product and P c is the world price of that product. S d + Q is the product supply curve after an import quota is imposed. Assuming there is no tariff, the import quota:

A.  will increase U.S. Treasury revenue by areas G + H.
B.  will increase U.S. Treasury revenue by areas E + F + G + H + J.
C.  may either increase or decrease the total revenues of foreign producers, depending on the elasticity of domestic demand.
D.  will increase the revenues of foreign firms by area E.

answer:

C.  may either increase or decrease the total revenues of foreign producers, depending on the elasticity of domestic demand.