(A) those that are against a

(B) those against a

(C) it is against a

(D) preventing those against a（E）

(E) it is to prevent those against a

最简洁的是:against a person还是to prevent crimes against a person?

否则就应该像E中把省略都补全么?

我觉得是要像E一样补出的。如果不补出it is, 会造成比较对象的不明确和不平行。而it在这里是形式宾语，所以还要补出to do不定式短语.

请NN斧正。

有道理！

OG中的解释是这样的

This sentence compares two actions, preventing crimes against property and preventing crimes against a person, in terms of difficulty. These actions should be described in grammatically parallel structures. Consequently, choices A, B, and D are faulty because they fail to parallel the first clause, which has it as a subject and is as a verb. Choice C contains it is but lacks to prevent those, words needed to complete the required clause and identify the other action in the comparison. Choice E is best: all of the elements necessary to describe the second action are presented in a form that is both idiomatic and grammatically parallel to the description of the first action. The question is moderately difficult.

as引导的句子都有这个要求嘛：补出助动词，而且要补全！

觉得用

to prevent those against a person也可以？

请NN指正。