Answer:
Adjective subordinate clause
Step-by-step explanation:
A subordinate clause, also called a dependent clause, is a clause that can't stand by itself as a simple sentence, unlike an independent clause. Subordinate clauses provide additional information and can function as a noun, an adjective, or an adverb.
The dog that chewed up my new shoes is named Oscar.
In the given sentence we have an adjective subordinate clause because it additionally describes the noun that comes before it - the dog. Adjective clauses begin with a relative pronoun or a relative adverb, in this case, the pronoun that.