Which of the following scenarios would be considered an unconstitutional use of state power?
(a) a state passes a law that increases the pay of state legislators.
(b) a state enacts a law prohibiting smoking in all public places.
(c) a state places a tax on furniture made overseas.
(d) a state raises the drinking age to 25 years of age.

The answer is  (C) A state places a tax on furniture made overseas. .

Explanation:

Taxing imported furniture isn´t one of the union states´ prerrogatives.

Imposing tariffs on foreign goods is an exclusive right of the federal Congress.

This is what Section 8 of the US Constituion says:

Section 8

1: The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States.

So, taxes on imported furniture must be laid by the US Congress.

you should think about the answers you give and expect the same form your questions.