we prefer that the plan _before being put into execution .

问题描述:

we prefer that the plan _before being put into execution .
a is fully discussed
b must be fully discussed
c be fully discussed
d will be fully discussed
b

正确答案应该是C,prefer在些作为一个由主观意愿发出的动词,有建议之意,应用虚拟语气,C答案正是省略了should的用法,原句在be前是有should的,此处被省略是可行的.