12. Rising inventories, when unaccompanied correspondingly by increases in sales, can lead to production cutbacks that would hamper economic growth.

(A) when unaccompanied correspondingly by increases in sales, can lead
(B) when not accompanied by corresponding increases in sales, possibly leads
(C) when they were unaccompanied by corresponding sales increases, can lead
(D) if not accompanied by correspondingly increased sales, possibly leads
(E) if not accompanied by corresponding increases in sales, can lead

Your question:
But I think correspondingly modify "unaccompanied" in A, which is a verb, and modify 'increased' in D, which is a adj... So my question is why an adv(correspondingly) modify a verb(unaccompanied in choice A) and an adj(increased in choice D) wrong???

rx_11, you are correct that correspondingly can modify the verb and the adjective increased. However, in the context of the sentence in question, this modification is incorrect. We will analyze each choice A and D individually. I will only concentrate on the use of correspondingly. I will not point out the other errors - when vs if & ambiguity with unaccompanied in Choice A and verb error in Choice D.

Choice A. The original sentence does not communicate the meaning in the most effective manner. Say this choice was written as (after correcting other errors so that we can concentrate only on 'correspondingly'):
Rising inventories, if not accompanied correspondingly by increases in sales, can lead to production cutbacks that would hamper economic growth.

It does not make sense for "corresponding" to modify accompanied. Corresponding implies similar. What does correspondingly accompanied mean - similarly accompanied - similar to what? Thus, this sentence is ambiguous.

Infact, the meaning will be more clear if it states "accompanied by corresponding increases in sales". Now it is clear that rising inventories are accompanied by similar increases in sales.

Choice D. (reworded with correct verb form)
Rising inventories, if not accompanied by correspondingly increased sales, can lead to production cutbacks that would hamper economic growth.

The sentence above is grammatically correct, but it distorts the meaning. The intended meaning is:

Rising Inventories (...if not accompanied) by corresponding increases in sales, can lead....
Here rising inventories shows a "TREND". And increases in sales shows another corresponding "TREND".
Contrast this with Choice D:
Rising inventories is still a TREND but now increased sales is NOT a Trend. It is a definite value.
Thus, the meaning has been distorted in Choice D.

I hope the above clarifies your doubt.

Regards,

Payal