New hardy varieties of rice show promise of producing high yields without the costly requirements of irrigation and application of commercial fertilizer by earlier high yielding varieties.
(A) requirements of irrigation and
application of commercial fertilizer by earlier high yielding varieties X
It doesn't make sense to say that the 'application of X' has a costly requirement because you're talking about the application itself
(B) requirements by earlier high yielding
varieties of application of commercial fertilizer and irrigation X
This one is wrong because you are saying 'varieties of application'...that's nonsensical
(C)
requirements for application of commercial fertilizer and irrigation of earlier high yielding varieties X
This one is wrong because you are saying 'the application of commercial fertilizer and irration has requirements, but what's costly are the irrigation and application in and of themselves
(D)
application of commercial fertilizer and irrigation that was required by earlier high yielding varieties X
This is wrong for two reasons: 'was' is singular whereas 'application of...AND ...' is plural. The more important error is that it suggests 'irrigation' can be applied
(E) irrigation and application of commercial fertilizer that were required by earlier high yielding varieties
CORRECT _________________
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