The core concept here is to understand the role of a 'tutor'. The correct answer is B because a tutor is typically a private teacher who provides instruction to an individual or a small group, outside of the standard school system. Option A is incorrect because it refers to a university teacher, which is not the same as a tutor. Option C is incorrect as it refers to the headteacher, who is the leader of a school, not a tutor. Option D is incorrect because it refers to a person giving lessons in a public school, which is a different context from private tutoring.