Americans who opposed the constitution were called:

Anti-federalists

Explanation:

Anti-federalists were those who opposed the ratification of the Constitution. Anti-federalists supported this view for several different reasons. Many believed that the Constitution gave too much power to the federal government. They were fearful that this would dilute the successes of the Revolutionary War. Others were afraid that the autonomy of the individual states would be violated, or that the Constitution did not protect the rights of people sufficiently.

the answer for 3 is b and the answer for 4 is d

it was douglas macarthur..