Congress passes a law imposing a tax on the owners of buildings containing lead paint. The law provides that funds derived from the tax shall be used to help finance research into the treatment of lead diseases. The validity of the statute under the U.S. Constitution is challenged in a legal pro-ceeding on the ground that one of the purposes of the tax is to discourage the use of lead based paint in buildings. The statute should be declared:

Select one:

a. Unconstitutional because Congress does not have the power to regulate the use of build-ing materials.

b. Unconstitutional if the law was passed for any purpose other than to raise revenue.

c. Constitutional as a valid exercise of the congressional taxing power.

d. Constitutional under the general federal police power.