Explanation:

- The given phrase is "The school or college in which one has been educated."

- Option 1: Alma mater

- Refers to the school, college, or university that someone attended.

- It is often used with pride or affection.

- Correct Answer

- Option 2: Alumni

- Refers to former students or graduates of an educational institution.

- Does not refer to the institution itself.

- Option 3: Graduate

- Refers to a person who has completed a course of study.

- It is not about the institution.

- Option 4: Mentor

- Refers to an experienced and trusted advisor.

- Unrelated to educational institutions.