Which of the following describes an individual who believes all actions are driven by selfishness?

The choice that accurately describes an individual who believes all actions are driven by selfishness is cynicism. Cynics tend to view human motivations as fundamentally self-serving, often expressing distrust in the sincerity or goodness of others' intentions. This perspective involves a skepticism towards altruistic claims, suggesting that purported benevolence masks selfish desires.

In contrast, the other terms do not denote this specific worldview. Wry refers to a dry or mocking sense of humor, which does not inherently include notions of selfish motives. Witty describes a person's ability to express cleverness in speech or writing, again unrelated to motivations behind actions. Yearning implies a deep longing or desire for something, which does not base its interpretation on human selfishness but rather on emotional or aspirational contexts. Thus, cynicism is the most fitting term for the belief in fundamentally selfish motivations.