请教另一语法题

It is as difficult to prevent crimes against property as (those that are against a ) person.

a, those that are against a

b, those against a

c, it is against a

d, preventing those against a

e, it is to prevent those against a

可否解释一下为何选E? 改成to prevent those against a 可以吗?

as...as...
对比,应该怎么确定对称部分呢?那B为什么不对呢