The sentence above uses Subjunctive Mood. I see that the answer choices can be broadly split based on "but" vs "but that" first. "But that" gives an incomplete meaning in the second clause and hence it is not correct. So, I eliminated A,C,D.

Between B and E, B should be eliminated because, "indicate" is not correct. That left me with only option E. [Just as "I suggest that you close the door" is correct while "I suggest that you should close the door" or "I suggested you to close the door" are incorrect]

Did I go the wrong way?

Hi all,

The fall in the Agriculture Institute's hostile disease threat level indicate that farmers should maintain a high level of production in the next quarter, but that the introduction of a new disease strain will pose a serious threat if suitable preventative measures are not developed.

Understanding the intended meaning of this sentence is the key to getting to the correct answer choice. We must remember that the meaning conveyed by the sentence must be logical.
The sentence says that the dip in the hostile disease threat level indicates two things:
a. farmers should maintain a high level of production in the next quarter (should = diktat)
b. introduction of a new disease strain will pose a serious threat if suitable preventative measures are not developed.

Error Analysis:
1. The singular subject “The fall” does not agree in number with plural verb “indicate”.
2. Use of “should” is not logical as it denotes that farmers are under some compulsion to maintain high level of production. The verb “indicate” denotes that something will happen in the future.
3. It is also not logical to say that dip in hostile disease threat level indicates something about the new strain disease. The parallelism is forced in the sentence that makes the meaning illogical.

PoE:

A. indicate that farmers should maintain a high level of production in the next quarter, but that: Incorrect for the reason above.

B. indicate that farmers are to maintain a high level of production in the next quarter, but: Incorrect. Repeats the SV error of choice A. But this choice rectifies the forced parallelism error.

C. indicates that farmers will continue at a high level of producing in the next quarter, but that: Incorrect. Repeats the forced parallelism error as in Choice A.

D. indicates that farmers should maintain a high level of production in the next quarter, but that: Incorrect. Repeats the “should” meaning and forced parallelism errors as in Choice A.

E. indicates that farmers will maintain a high level of production in the next quarter, but: Correct. This choice rectifies all the errors of the original sentence.

Hope this helps.
Thanks.
Shraddha
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