Question

complete the sentence with the best relative pronoun. the man witnessed the car accident immediately called the police.

Explanation:

To complete the sentence, we need a relative pronoun that refers to "the man" (a person) and acts as the subject of the relative clause "witnessed the car accident". The relative pronoun "who" is used for people in such cases (when the pronoun is the subject of the relative clause). "That" can also be used for people in informal or restrictive relative clauses, but "who" is more appropriate for referring to people as the subject.

Answer:

who (or that, but "who" is more precise for referring to a person as the subject of the relative clause)