An adjective clause functions as an adjective, that is, it gives some information about a noun in a sentence (or a pronoun) ( information which is not an action).
The noun modified here is "knife" and the information about the knife, that is the complete adjective clause is "<span> that his dad gave him.
"</span>
6 might be because it has the right definition?!?!
All nouns: Jade, competition, city park. Frisbee is an adjective.
