Answer:
<em>Subordinate clause.</em>
Explanation:
The main clause is a type of clause which is consisted of a subject and a verb and it can function on its own, it even can represent a sentence.
The subordinate clause is a type of clause <em>that can not function alone</em>, usually, it complements the main clause, which we, in this specific case, miss. What we also can notice from the given clause is that it starts with a relative pronoun which, <em>the subordinate clauses are characterized by starting with a relative pronoun (whose, whoever, that...) or a subordinate conjunction (since, because, until...)</em>.