The correct answer is A) Congress would have too much power over states.
Anti-Federalists feared that by turning the constitution into the law of the land, the States would loose too much power while the Federal government would be extremely strong.
Anti-Federalists, by their name, opposed the power of the Federal government and beleived States should have far more independence from Congress. It was a strong movement in the early years of the country which opposed the ratificaiton of the 1787 Constitution.
While the Constitution was ratified, the Anti-Federalist movement was successful in getting the Bill of Rights passed.