Who represents all the people of a U.S. state?

The choice of a U.S. Senator as the representative of all the people of a U.S. state is correct because U.S. Senators are elected to serve in the upper chamber of Congress, which represents the interests and rights of the residents of their entire state, rather than a smaller district or local area. Each state is allotted two senators, regardless of its population size, ensuring that all states have equal representation in the Senate. This role is crucial in the federal legislative process, as senators participate in making laws, overseeing the executive branch, and representing their constituents on national issues.

In contrast, a U.S. Representative serves a specific congressional district within a state, meaning they represent only the people living in that district instead of the whole state. The Governor is the head of the state’s executive branch, managing state affairs but not necessarily representing the state in a legislative sense. A State Senator operates within the state legislature and represents the interests of a specific legislative district within the state, similar to a U.S. Representative but at the state level. Thus, the U.S. Senator's role encompasses serving all citizens in their state, making this the most fitting choice for the question.