Answer:
Relative Clause.
Explanation:
A relative clause is the clause that consists of a subject and a verb. This clause begins with relative pronouns such as 'who, whose, whom, where, when, that, etc.' A relative clause helps in relating to something else in the sentence.
A relative clause is a dependent clause that helps in the identification of the noun that precedes it.
For example, The girl, whom the narrator met in the train, was blind.
In the above stated example, whom' is the relative pronoun that is used to identify the noun that preceded it, that is 'the girl.'
So, the correct answer is a relative clause.