Concept:A relative pronoun phrase connects a relative clause to the noun it modifies.Explanation:The correct phrase must refer back to a place, situation, or time mentioned in the sentence."In which" means "in that place/situation" and correctly introduces the relative clause."What" does not follow a previously mentioned noun."From where" suggests a starting point or origin, not a location where something happens."In that" usually means "because", so it is not the best relative phrase here.Answer:A. in which