Which of the following is NOT a Cabinet-level position?

The President of the Senate is not a Cabinet-level position because this role is primarily a legislative one, associated with the U.S. Senate. The President of the Senate is typically the Vice President of the United States, whose main responsibility is to preside over Senate sessions and maintain order.

In contrast, the Secretary of State, Secretary of Defense, and Attorney General are all Cabinet-level positions within the executive branch of the government. These roles are part of the President’s Cabinet and are responsible for advising the President and managing specific departments related to foreign affairs, defense, and justice, respectively. Each of these positions plays a vital role in the administration's execution of federal policies and operations in their respective areas.