Finally reaching a decision on an issue that has long been politically charged

in the Pacific Northwest, politicians decided to postpone by at least five years

an ambitious plan to protect wild salmon and other endangered fish, instead

of which they proposed a series of smaller steps, by which they intend to protect the fish.

A.     politicians decided to postpone by at least five years an ambitious plan

to protect wild salmon and other endangered fish, instead of which they

proposed a series of smaller steps, by which they intend

B.     politicians decided to postpone by at least five years an ambitious plan

to protect wild salmon and other endangered fish, proposing instead a

series of smaller steps intended.

C.    politicians decided to postpone by at least five years an ambitious plan

for protecting wild salmon and other endangered fish, and instead they

proposed a series of smaller steps, intending.

D.    an ambitious plan to protect wild salmon and other endangered fish was

postponed by politicians, who instead proposed a series of smaller

steps, intending.

E.     an ambitious plan to protect wild salmon and other endangered fish has

been postponed by politicians, proposing instead a series of smaller

steps intended.

请问C的错误是什么？

c 肯定错 

for 表用途  表目的话不简洁

个人认为：第一步：根据逻辑主语，排除D、E；第二步：A中instead of 是介词，后面不能跟句子；

A错；instead 是副词，一般修饰动词；C错；而且C表达不如B简洁，C错。