What does re-apportionment involve?

Re-apportionment specifically refers to the process of redistributing the number of representatives among the states based on the results of the decennial census. This procedure is outlined in the Constitution and occurs every ten years. As the population of the United States changes, some states may gain seats in the House of Representatives while others may lose them, reflecting shifts in population. This is essential for ensuring that representation in Congress is proportionate to the population of each state, thereby maintaining the principle of equal representation.

The other options do not correctly define re-apportionment. Changing the Constitution involves a more complex and rarely executed process and is unrelated to the flow of representatives in the House. Redistricting state boundaries deals with drawing the lines of congressional districts within a state but does not involve the reallocation of the number of representatives. Adjusting the number of senators does not occur through re-apportionment since each state has two senators, regardless of population changes. Thus, option C accurately captures the essence of re-apportionment.