the number of senate seats held by each state is

a. set by the census bureau
b. based on state populations
c. the same as the number of house seats
d. fixed by the constitution

c.

Nope. Check Article I, Section 2.

http://www.senate.gov/civics/constitution_item/constitution.htm

Oops -- It's Section 3.

The correct answer is d. fixed by the constitution.

According to the United States Constitution, the number of Senate seats held by each state is fixed. Each state is allocated two Senate seats, regardless of its population size. This means that every state is equally represented in the Senate, regardless of its population. This allocation was established by the Founding Fathers in order to provide equal representation to each state, regardless of size.

Actually, the correct answer is not c. The number of Senate seats held by each state is not the same as the number of House seats.

The correct answer is d. The number of Senate seats held by each state is fixed by the constitution. The United States Constitution specifies that each state is entitled to two seats in the Senate, regardless of the state's population.

In contrast, the number of seats in the House of Representatives is based on state populations. The census bureau conducts a census every 10 years to determine the population of each state, and then the number of House seats for each state is allocated based on their population.

So, in summary, Senate seats are fixed by the constitution while the number of House seats is based on state populations.