Explanation

Reading the question: the phrase "best supported by" is an example of test maker's understated language, as discussed in New Exercise system. So we have a filter; we can prove by stronger terms, looking for a correct answer that is not just supported by the prompt, but logically required by it. We can't be certain that there will be such an answer choice, but if there is, it will be certainly correct.

Applying the filter: We'll go out of order. Choice (B) need not be true based on the argument; the existence of other competitors is completely unrelated. Choice (B) is out. (C) is probably false; steel appears to be an input to their businesses, not a good, but we don't really have definitive information to defend (C). Choice (C) is out. Choice (D) need not be true. The relative position of the company speaking has improved, but they don't say from what position. Choice (E) need not be true. We know that steel costs go up, but we don't even know what the source of revenue for the competitor is, so we don't know that they even changed, much less declined considerably.

Logical proof: We are left with (A). Might this be logically required by the argument? We can attempt the negation test. If the competitor had a massive cash reserve, it might still have more cash than the speaker's company after taking a hit this year. So, if the conclusion is true, there is an upper limit on the cash that the other company has on hand. And, since we don't know how much it's depleted by, for the argument to be correct no matter what, the competitor's reserves must be no higher than ours in the prior year, as stated by (A). Answer choice (A), indeed, is well supported by the prompt. The correct answer is (A).