Which of the Following Is a Characteristic Feature of Concurrent

Which of the following is a characteristic feature of concurrent powers?​ 

A)  They include powers held by the U.S. federal government which may be shared with the states at the former's discretion.​ 
B) They apply only within the geographic area of a state and can be overridden by national policies. 
C) They include functions that the Constitution delegates exclusively to the national government. 
D) They allow states to levy taxes on goods being imported from other states and countries. 
E) They allow the U.S national government to impose taxes on exported goods.