Final answer:
Federalists like James Madison were concerned that an explicit list of prohibitions for the government in the Constitution could imply that unspecified rights were unprotected, potentially leading to an overly powerful government and constraining individual liberties.
Step-by-step explanation:
Federalists like James Madison were worried about including an explicit list of things the government can’t do in the Constitution because it could implicitly suggest that any rights not listed may not be protected. This concern is identified in Option B: They feared the government might become too powerful. However, Madison and other Federalists believed that a bill of rights was unnecessary because the federal system, which divided power between the national and state governments, as well as the separation of powers within the federal government, would adequately prevent any one branch from becoming too strong. They argued that the limitations placed on the government in Article I, Section 9, and the enumerated powers of Congress would be sufficient to protect liberties without a bill of rights. The concern was that listing specific prohibitions could limit the scope of rights to only those listed and potentially undermine those not listed.