Explanation:

- The group of words: "A non-professional who is inept at a particular activity" refers to someone lacking expertise or skill.

- Option 1: Expert

- Definition: A person with comprehensive and authoritative knowledge or skill in a particular area.

- Relevance: Opposite of the group of words; not correct.

- Option 2: Amateur

- Definition: A person who engages in an activity for pleasure rather than as a profession. Often implies a lack of skill.

- Relevance: Fits well with the description as it can mean someone who is not professional and potentially inept.

- Option 3: Director

- Definition: Someone who supervises or oversees an organization or department.

- Relevance: Does not relate to being inept or non-professional.

- Option 4: Fatalist

- Definition: Someone who believes that all events are predetermined and inevitable.

- Relevance: Not related to skill or professionalism.