What is the primary duty of the Speaker of the House?

The primary duty of the Speaker of the House is to preside over the House of Representatives. This role involves managing the legislative process, ensuring that debates are conducted fairly, and maintaining order during discussions. The Speaker also has significant influence over the legislative agenda, determining which bills come up for a vote and guiding the proceedings.

In this capacity, the Speaker can facilitate communication among members, represent the House in ceremonial functions, and play a key role in negotiations with the Senate and the President on legislative matters. This position is vital for the functioning of the House and upholding its legislative responsibilities.

The other duties listed pertain to different roles in government. Signing bills into law is the responsibility of the President, leading the Senate is typically the role of the Vice President or the Senate Majority Leader, and acting as Commander in Chief is a power reserved for the President regarding military affairs. Thus, the Speaker's specific function in the House clearly distinguishes this answer as the correct choice.