According to the Constitution, how is the number of electoral votes per state determined?

The number of electoral votes per state is determined by the number of congressional members that the state has, which is the correct answer. Each state receives a number of electoral votes equal to the total number of its Senators (always two, regardless of population) plus the number of its Representatives in the House. The House of Representatives' membership is based on the population of the state, as measured by the most recent decennial census. Thus, if a state's population increases and it gains more Representatives, its electoral vote count will also increase.

This system was designed to balance the influence of populous states with less populous ones, reflecting both the democratic principle of representation based on population and the equal state representation in the Senate. Other options do not reflect how electoral votes are allocated; for instance, they do not take into account the constitutional structure of Senate and House representation.