Why did the anti-federalists insist that the bill of rights be added to the constitution? a. to act according to the rule of law b. to gain approval from the federalists c. to create a stronger central government d. to guarantee the rights of individuals

Correct  D. To guarantee the rights of individuals

Explanation/context:

The Anti-Federalists opposed ratification of the US Constitution.  The Articles of Confederation, in place prior to the ratification of the Constitution of the United States of America, had granted stronger authority to the states.  Patrick Henry and other Anti-Federalists were concerned about too much power winding up in the hands of the federal government and its executive branch, thus allowing a small number of national elites to control the affairs of the USA.  They feared this also would diminish the rights and freedoms of individual citizens.

The Bill of Rights, laid out in the first ten amendments to the Constitution, provided some reassurance to Anti-Federalists after the fight over ratification, because these amendments to the Constitution served to guarantee that individuals' rights would be protected under federal law.