What is the purpose of the necessary and proper clause in the constitution?
a. it allows congress to make laws not covered by its expressed powers.
b. it permits the president to overrule congress.
c. it allows state governments to expand their powers.
d. it declares congressional actions to be “the supreme law of the land.”

The purpose of the Necessary and Proper Clause in the Constitution is to A. allow Congress to make laws not covered by its expressed powers.  

The implied powers are the ones that allow the American Congress to make decisions concerning with the subjects that are not mentioned in the Constitution. The Congress is expected to use these implied powers only as and when necessary and that too in the most reasonable manner.

Thus, the implied powers are bestowed upon the Congressmen with a mention of the clause of necessary and proper use of the power.