Answer:
The car, which took Miah months of saving money to buy, is parked in the garage.
The bicycle that Kameron has had since he was ten years old is still in great shape.
Sierra met the boy whose parents recently opened the restaurant across the street.
Step-by-step explanation:
Restrictive relative clauses contain a relative pronoun that can sometimes be omitted, such as which, that or whose. In that respect, the chosen sentences two and three have restrictive or defining relative clauses, which possess essential information.
On the other hand, non-restrictive relative clauses like the first sentence have a relative pronoun that cannot be omitted and contain additional information. In fact, the relative clause could be omitted entirely and the sentence would still make sense.