How many U.S. Senators are there?

The correct answer is one hundred (100) because the United States Senate is composed of two senators from each of the 50 states, totaling 100 senators. This design is established in the U.S. Constitution, specifically in Article I, which outlines the legislative branch of the federal government. As a fundamental component of the bicameral legislature, the Senate plays a crucial role in law-making, representing the states at the federal level, and serving critical functions such as the ratification of treaties and the confirmation of federal appointments.

The other choices reflect incorrect numbers based on the fixed structure of the Senate. There are not fifty senators because that would mean only one senator from each state. Ninety senators is also incorrect since it would imply a reduction of the total number from the established norm. Lastly, one hundred and fifty is an inflated figure that does not align with the Constitution or the current composition of the Senate.