Which clauses in these sentences are restrictive?
1.the girl who owns a red car is the one we are looking for.
2.the dog that ate my homework is called henry.
3.i’m saving the muffins that have cherries for my sister.
4.the smile that she gave them was beautiful.

When we say restrictive clause, this means that the clause in the sentence serves as an additional information about the subject but cannot be omitted since it will change the whole thought of the sentence. 
1. who owns a red car
2. that ate my homework
3. that have cherries
4.  that she gave them
Hope this answer helps.

I'm sorry, i can't you without the passage to read. if you write down the passage, i'll be glad to you