Sentence Correction

Though caterpillars transform large amounts of plant matter into animal tissue and wastes, and therefore hold an important place in the food chain, they are so voracious that they have become an economic threat to farmers whose crops they eat.

a)they are voracious that they they have become an economic
b) they are of such voracity, they have become an economical
c)so voracious are they as to become an economical
d)such is their voracity, they become an economic
e)there is so much voracity that it has become an economical

The OA is a.
But i chose c(since i didnt have any other choice left).I am sure economical is better than economic here.

please clarify this?.(this ques is from Kaplan Test)

Yes, economical means inexpensive; economic is the adjective for economics, the science (or art).

happy diwali!!

Economical means efficient or inexpensive, but not in the context of this sentence

heshamelaziry wrote:Economical means efficient or inexpensive, but not in the context of this sentence

Can you please elaborate heshamelaziry?.
Do you mean to say A) is correct?.how?.

Why we shouldnt chose an answer option with "economical"? .

ikruz wrote:

heshamelaziry wrote:Economical means efficient or inexpensive, but not in the context of this sentence

Can you please elaborate heshamelaziry?.
Do you mean to say A) is correct?.how?.

Why we shouldnt chose an answer option with "economical"? .

I found out that both have two different meanings; economic strictly and only relates to an effect on the financial status of say "USA". Here the effect is ambiguous. Could be positive or negative. For example: The gobal financial melt down will have an economic effect on the health of the US economy. I can't say "economical" because it will mean positive effect.
On the other hand, Economical means a positive effect, and usually I see it at the end of the sentence, for example: Hybrid cars are economical or Hybrid cars are economical for consumers.

So, in this sentence if we say "economical threat", the sentence intended meaning will fall apart. Look for the message that the sentence wants to deliver.


Hope this helps