Which of the following is a check on presidential power?

The Senate's advice and consent serves as a vital check on presidential power by requiring the President to gain Senate approval for certain key actions, particularly appointments and treaties. This process is rooted in the U.S. Constitution, which specifies that the Senate must confirm presidential nominations for federal judges, ambassadors, and high-level officials in the executive branch, as well as approve treaties negotiated by the President before they become legally binding.

This requirement ensures that the Senate, which represents the states and acts as a critical component of the legislative branch, has a role in the decision-making process, balancing the President's power. It prevents unilateral actions that could undermine the broader interests of the country and exemplifies the system of checks and balances designed to maintain a separation of powers among the branches of government.

Other options, while they may influence presidential power or governance, do not provide the direct and formal check that the Senate's advice and consent mechanism does.