The correct answer should be A. Demographics
Demographics encompasses both the number of people and the various groups of people based on ethnic and racial heritage, and gender, sex, age, and similar.
I think its going to be the 2nd option class's. even the you usually put an apostrophe after the s when the noun is plural, I believe class's is a collective noun in this place which take a singular approach with apostrophes
Kate is the best <em><u>of </u></em> the three.
