The underlined portion contains two pronouns ("they" and "whose"), so check that they are being used properly. "They" clearly refers to the oil prices, and "whose" clearly refers to airlines. The pronouns match up clearly and logically. There appears to be no error.

(A) and (B) begin with "they," (C) and (D) begin with "for," and (E) begins with "it."

(B) contains a couple of problems. First, the phrase "may potentially" is redundant. If something "may" happen, that already implies potential. There is no need for both words. Further, the pronoun "their" at the end is ambiguous, as it could refer to oil prices or airlines. That eliminates (B).

The first half of the sentence begins with "While," making it a dependent clause. What follows the comma should be an independent clause (i.e., a sentence that can stand by itself). There's no need for the conjunction "for" as the first half is already dependent. That eliminates (C) and (D).

The potential cause of disaster is "oil prices," which is a plural noun. That should be replaced with "they," not "it." That eliminates (E).

There is no error in the original sentence, and all other answer choices are flawed. That makes (A) the correct answer.