sentence correction; cloning technology

[wawatan]

With cloning technology, scientists are approaching
what has long been the ultimate goal of modern
husbandry: achieving a consistency of quality and
production in farm animals as once thought to be
limited to manufactured goods.
(A) achieving a consistency of quality and production
in farm animals as once thought to be
(B) achieving farm animals with a consistency of
quality and production as were once thought of as
(C) achieving in farm animals a consistency of
quality and production that was once thought to be
(D) achievement of farm animals whose consistency
of quality and production are the same as what were
once thought to he
(E) achievement of farm animals at a consistency of
quality and production once thought of as

why is A wrong?

OA is C

[ksh]

IMO A is wrong on the following counts:
1. In the second clause verb do not match
2. "as" has been used in the second clause which is improper. 'that' would be proper narrowing the meaning referred.

IMO C is the correct ans

[wawatan]

so the "as" in answer choice A is used for comparison?

when are we allowed to use as in a sentence?

[pranavc]

Well, "as" would be used if the sentence was written as "the same consistency in quality" etc. "As" would be used when making a distinct comparison. In option "A", it is out of place. I hope this helps.

Pranav