Florida Passes a Tax That Applies Only to Foreign Ships

Florida passes a tax that applies only to foreign ships that unload cargo at the ports of Miami and Tampa. This tax is:

A) unconstitutional; it interferes with foreign trade
B) unconstitutional; states must charge fees for the use of public facilities
C) constitutional; it is related to benefits received
D) constitutional; it only applies to foreign merchants, so it does not discriminate against interstate commerce
E) constitutional so long as the federal government imposes a similar tax