Final answer:
An actor is most likely to possess a high level of interpersonal intelligence according to Gardner's Multiple Intelligences Theory, as it entails understanding and interacting effectively with others, which is essential in acting.
Step-by-step explanation:
According to Gardner's Multiple Intelligences Theory, the person MOST likely to possess a high level of interpersonal intelligence would be an actor. Interpersonal intelligence is one of the eight intelligences proposed by Howard Gardner, characterized by the ability to understand and interact effectively with others. Actors often need to collaborate and communicate effectively with fellow performers, directors, and audience members. They also need to understand characters' emotions and motivations, which requires strong interpersonal skills. In contrast, the other professions listed—mathematician, musician, and athlete—might require different types of intelligences, such as logical-mathematical intelligence for a mathematician, musical intelligence for a musician, and bodily-kinesthetic intelligence for an athlete.