The correct answer is:
b. They were afraid the national government would be dominated by states with larger populations.
Small states were concerned that representation based solely on population would give larger states too much power in the national government, thereby diminishing the influence of smaller states in legislative decisions. This concern ultimately contributed to the emergence of the Great Compromise during the Constitutional Convention, which established a bicameral legislature with both proportional representation (in the House of Representatives) and equal representation (in the Senate).