The correct answer is A) Slaves should be counted among a state's population for the purpose of deciding a state's number of congressional representatives.
When developing the new constitution at the Constitutional Convention, delegates from the 13 states had to determine whether or not slaves would be considered part of the population. This is due to the fact that slaves were often considered property, not people, in the eyes of the law.
With this in mind, Southerners wanted to make sure that slaves counted as people in the census. This is due to the fact that a bigger population results in more representatives for a state in the House of Representatives. Having more representation in the House of Representatives is important because the House and Senate are responsible for making national laws.
On the other hand, Northerners did not want slaves to count. They did not want slaves to count because this would result in the South having more political power than the North.
This is why the two sides agreed to the 3/5ths Compromise. In this compromise, every 5 slaves would count as 3 people towards the population.