Final answer:
The separation of powers is designed to prevent any one branch of government from becoming too powerful, thereby protecting against tyranny. James Madison emphasized this in Federalist No. 51. The correct answer for the student's question is 'b) to prevent tyranny by any one branch'.
Step-by-step explanation:
The primary reason for the separation of powers in a government is to ensure that no single branch becomes too powerful and enforces a tyrannical rule. The founders of the United States established a system in which the government was divided into three branches: the legislative, the executive, and the judicial, each with its own distinct powers and responsibilities. This division was deliberately intended to create various checks and balances within the system, with each branch having the ability to restrict the powers of the others to prevent any potential overreach.
James Madison, in Federalist No. 51, highlighted that ambition must be made to counteract ambition, ensuring that the personal motives of officeholders in each branch would limit any attempt by the other branches to overstep their authority. Thus, Madison reassures that the separation of powers, in combination with the federal system that divides power between the national and state governments, would prevent any part of the government from becoming too strong, thereby protecting the nation from tyranny.
The correct answer to the student's question is 'b) to prevent tyranny by any one branch'. This separation of powers is fundamental to the operation of American democracy, and it is a system that requires cooperation and compromise among the different branches of government.