[問題]大全987-610

[Alycia]

610. 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

Ｉchose B but the answer is E...why can't we use "when" in this case? and what difference does it make to use "if?"
Thanks

[schung0529]

610. 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

Ｉchose B but the answer is E...why can't we use "when" in this case? and what difference does it make to use "if?"
Thanks

B 一定錯~ 因為 inventories 要加單數動辭lead
if + 現在式 表示假設語氣~
不過還請高手出面解釋吧~