How are congressional districts determined?

Congressional districts are determined primarily by population. This process is known as "reapportionment," which occurs every ten years after the national census. The United States Constitution mandates that congressional seats be allocated among the states based on their population relative to one another. This means that each district within a state must have roughly equal populations to ensure fair representation in the House of Representatives.

The drawing of these districts is then done by state legislatures, and this process can be influenced by various factors, including political considerations, which leads to practices like gerrymandering. However, the fundamental principle is that districts should reflect population size to maintain the "one person, one vote" standard of representation.

The other options discuss factors that may influence how districts could be configured, such as geographic boundaries or state resources, but they do not address the primary criterion of population that drives how congressional districts are ultimately determined.