Why did anti-federalists oppose the constitution?
a. because it provided for separation of powers
b. because it did not have a bill of rights
c. because it favored large states
d. because it could not be amended

The main reason why the Anti-federalists opposed the Constitution is because "it did not have a bill of rights", which they thought meant that the federal government would eventually stomp on the rights of states and citizens. 

The correct answer in my opinion is "u.s. government attempt to open up the black hills to development.  "