请教og 121

The concept of the grand jury dates from the twelfth century, when Hery II of England ordered panels of common citizens should prpare lists of who were their communities' suspected criminals.

(E) to prepare lists of suspected criminals in their communities

答案选对了，是（E），但我的问题是（E）中的their会不会有歧异的指代呢？是指citizens还是criminals呢？如果说就近指代的话，不久是指代criminals了？那就说不通了。请NN解答一下。

谢谢！

1. 选最优，哪怕their指代歧义也只能是E

2. 逻辑上考虑

3. their这里也可理解为是of common citizens 的缩写

4. 这题反过来是个很好的证明：就近指代不一定就是指代前面最近出现的单复数一致的名词。

为什么A不正确？

A. shoule prepare lists of who were their communities' suspected criminals

虚拟语气不是也可以么？

宾语从句不可省that, 同时命令式虚拟语气必须去掉should.

order sb. doing sth.是错误的么?

错的，只有order sb. to do

和order that sb.(should) do

在GMAT语法中，虚拟语气中的should都省略

对这句的理解有点困惑，请问这里的prepare 是揭发，检举的意思吗？查了字典好像没有。谢谢！