We can make assumptions for this one.

With (1), assuming we sold 100 units for $100 each, then the revenue is $10,000. With the price and sales change, we now sell 111.11 units (don't worry about the facts that we are selling 0.11 of a unit lol) for $90.91. I can't do the math off the top of my head, but surely one can figure out what 111.11*90.91 is, and then we compare the answer against $10,000 for the percentage change in revenue. Now, clearly if we assume 200 units instead, then the calculations are just doubled. Any change we make to the assumption will pervade through the calculations, so the percentage change remains the same.

(2) is not sufficient. It actually doesn't matter at all in this case.

So A.

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Not a professional entity or a quant/verbal expert or anything. So take my answers with a grain of salt.