The correct answer is C) they were partially counted in the census.
The agreement that the delegates reached regarding enslaved people and representation with the three-fifths compromise was that "they were partially counted in the census."
During the Constitutional Convention of 1787 held in the city of Philadelphia, Pensylvania, the 55 delegates that participated agreed on the three-fifths compromise. This agreement allowed slaves to be counted as 3/5 of a person when considering representation and taxation. Instead of being ignored, slaves working in the southern plantations were minimum considered. However, this was important because those states had more electoral power.
The other options of the question were A) they were not to be counted in the census at all. B) they were counted in the census as full equals. D) they were counted in the census in certain states.