Answer:
The answer to your question would be that the bolded words are a noun clause.
Step-by-step explanation:
A noun clause is a dependent clause that acts as a noun. Noun clauses begin with words such as that, which, what, where, who, etc. Just as nouns, they can act as subjects, direct objects, indirect objects, predicate nominatives, or objects of a preposition. In this case, the noun clause is acting as the subject of the sentence.