The correct answer is B) The power to ratify changes to the Constitution.
The federal government is given the ability to tax citizens multiple times. This includes Article 1 Section 8 of the US Constitution and the 16th amendment (which establishes the federal income tax).
The power to regulate interstate commerce is also in Article 1 Section 8 of the US Constitution. This was further reinforced by the Supreme Court case Gibbons vs. Ogden.
The US Constitution also explicitly gives the right to sign treaties to the federal government.