Which relative clauses use preposition placement correctly? Select all that apply.
the supply company from which we buy steel✓Correct answer
the supply company which we buy steel from✓Correct answer
the supply company from that we buy steel
the supply company from who we buy steel
Explanation
Both fronting from before which and stranding from at the end produce standard relative clauses about the company. From that is invalid in the fronted pattern, and from who incorrectly treats the nonhuman antecedent as a person.