I'm assuming you understand where the inflation bit comes from so I won't explain that. The import price index, as well as the terms of trade, is something a lot of people misunderstand. It measures the relative PRICES of imports and exports, not neccessarily their volumes or whether our trade surplus is positive etc. So if export volumes decrease, this will have no impact on the TOT as long as prices remain constant. Having this knowledge now, it is clear why it isn't A.
Does this make sense?
And on a technical level, the question I think is wrong because the import price index actually has nothing to do with export prices but thats the only option left that makes sense. Is it D?