Final answer:
The Anti-Federalists wanted a Bill of Rights to protect individual freedoms within the Constitution, fearing that without such protections, the federal government might infringe upon civil liberties.
Step-by-step explanation:
The group that wanted a Bill of Rights added to the Constitution was the Anti-Federalists. They voiced strong concerns about the concentration of power and the potential for governmental abuse within the newly drafted Constitution. Insistent on the need for protections for individual liberties, the Anti-Federalists believed that a Bill of Rights was necessary to safeguard citizens against an overreaching central government. Their contention was that the new government might extend its powers beyond what was agreed upon, potentially infringing upon the rights and freedoms of the people.
While Federalists argued that a Bill of Rights was unnecessary and could even be perilous, because rights not listed could be ignored, the Anti-Federalists countered this perspective with a demand for clear and unequivocal protection of certain freedoms. Therefore, the correct answer to the student's question is 'a) Anti-federalists.'