Explanation:

The tone of the statement is negative and it conveys that higher prices lead to less profits and then goes on to talk about another negative issue. Thus, clearly, the second would add to the stress and not reduce it. Hence, we can eliminate ameliorating and relieving, both of which mean to make a situation better.
Aggravate is correct in terms of meaning (to worsen) but incorrect grammatically as aggravating should have been used.
Compounding means to make (something bad) worse and is a perfect fit.
Hence, option C is correct.