Sentence Correction

While depressed property values can hurt some large investors, they are potentially devastating for homeowners,whose equity - in many cases representing a life's savings - can plunge or even disappear.

A they are potentially devastating for homeowners,whose
B they can potentially devastate homeowners in that
C for homeowners they are potentially devastating, because their
D for homeowners, it is potentially devastating in that their
E it can potentially devastate homeowners,whose

The correct answer here is A and I understand why other choices are wrong. However, for the first time I thought that the use of they is ambiguous because it might refer to investors right?

Actually, I agree with you, yes. Good noticing! But as you say, it's the best of the answer choices -- all the others are even worse .

Tega1984 wrote:While depressed property values can hurt some large investors, they are potentially devastating for homeowners,whose equity - in many cases representing a life's savings - can plunge or even disappear.

A they are potentially devastating for homeowners,whose
B they can potentially devastate homeowners in that
C for homeowners they are potentially devastating, because their
D for homeowners, it is potentially devastating in that their
E it can potentially devastate homeowners,whose

The correct answer here is A and I understand why other choices are wrong. However, for the first time I thought that the use of they is ambiguous because it might refer to investors right?

The subject of the dependent clause is " property values" so the pronoun THEY (a nominative case pronoun) can refer to subject only not to the object (investors) of the dependent clause.

Should not we look for the parallelism in this sentence?

So I tought B would be the answer, because it provides parallism. "....can hurt, can devestate..."