OG128 是否用were消除了歧义？

128. 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

(B)   requirements by earlier high-yielding varieties of application of

commercial fertilizer and irrigation

(C)  requirements for application of commercial fertilizer and irrigation of earlier high-yielding varieties

(D)  application of commercial fertilizer and irriga­tion that was required

by earlier high-yielding varieties

(E)   irrigation and application of commercial fertil­izer that were required

by earlier high-yielding varieties

E中的that是否构成了指向fertilizer的歧义呢？但是were消除了这种

歧义。

还是说，that本来就在语法上指向irrigation and application？？