Why did federalists argue for a separation of powers?

no single branch of government would have too much power.
the president should have more power than the other branches.
power would be divided equally between federal and state government.
trying to balance three branches of government would be impossible.

Correct answer choice is :

The supporters of the intended Constitution declared themselves Federalists. Their chosen name indicated a commitment to a loose, decentralized system of government. In many regards federalism which indicates a strong central government was the opposition of the proposed plan that they carried.

the answer might be either a or c. can't be too sure , because i searched the web, but no valid answers came through.

depends on what they need