The clauses in these sentences that are restrictive are:
1.who owns a red car
2.that ate my homework
3.that have cherries
4.that she gave them
All these clauses are modifying the noun that precedes them.
Restrictive clauses limit or identify such nouns and cannot be removed from a sentence without changing the sentence’s meaning.
Restrictive clauses are usually introduced by the relative pronouns that, who, whom, or whose. A restrictive clause can have an identifying function. A restrictive clause can have a limiting function. as well.