10. suppose you walk into the capitol in washington and ask to interview the most prominent person in the entire congress. if they accept, you'll get an appointment with the

Congress is a bi-cameral body and the two chambers are: the House of Representatives and the Senate. So it would be one of the two leaders of those houses. The problem is that both houses are considered of equal importance, so it's not exactly clear.

It is usually assumed that the Speaker of the House of Representatives represents the whole congress, so I would go with this option. However, it's a conventional role, not a strict one.