TBH Im going to guess this but i think its going to be <span>mobility</span>
<span>People of the highest social class in society belong to the upper-upper class, aristocrats, or elites. These people comprise 1 to 3 percent on the American population, and come from old money. There are various factors used to determine an upper-upper class member or elitist, but the main one is wealth.</span>
C is your answer
Hope I helped you today ;)