John F. Kennedy was a very privileged man from a powerful family. His father was a rich businessman who served at one point as the US ambassador to Great Britain. By contrast, Richard Nixon was not from any sort of privilege. He was, instead, the son of a small businessman from the town of Yorba Linda, in California. Thus, the answer is D.
While Kennedy was privileged and attended private schools his whole life, Nixon was neither. He had to work in the family store from a young age. He attended public schools through high school. Nixon was from a middle class family where Kennedy was from a rich family. Nixon was Protestant where Kennedy was Catholic. Nixon was a supporter of Eisenhower's policies (in fact, he was Eisenhower's vice president). As a Democrat, Kennedy was not a supporter of Eisenhower.
Some commentators believe that Nixon's drive to overcome this modest childhood was part of what drove him to obsess about his enemies, eventually leading to his downfall in the Watergate scandal.