K12 unit review: why is the united states congress divided into two houses (house of representatives and senate)

The reason why the United States Congress is divided into two houses is because, smaller states were afraid of losing power to larger states and the larger states were afraid that even though their population was larger, they would not be proportionally represented in the legislature. Because of these concerns, the compromise addressed the legislature with two houses. The House of Representatives is based on population. While in the Senate, the states would be equally represented.

Idont know which one is right   but i know that c is wrong and a might be wrong