The Founding Fathers gained support for the Constitution by promising that

Aall free males would be able to vote.

Eliminate

Bthe President would be from the South.
Ca Bill of Rights would be established.
Dcitizens would not be required to pay taxes.

Verified Answer :

The correct answer is C.

The Bill of Rights ensures that each free male would have the same undeniable rights that couldn't be abused by any power. This was important to the people, considering they just became independent from a royal power that disregarded the rights of the people.

The correct answer was

Ca Bill of Rights would be established.  

Thanks Kmatras1