求助：OG Test SC 40 ,that 用法

babygogogo

in 1995 Richard.Stallman，a well-know critic of the patent system,testified in Patent Office hearings that, to test the system,a colleague of his had managed to win a patent for one of Kirchoff's laws,an observation about electic current first made in 1845 and now in virtually every textbook of elementary physics.

A.laws,an observation about electric current first made in 1845 and
B.laws,which was an observation about electic current first made in 1845 and it is
C.laws,namely,it was an observation about electic current first made in 1845 and
D.laws, an observation about electic current first made in 1845 ,it is
E.laws that was an observation about electic current, first made in 1845 ,and it

选A。
这句话的主语是 Richard testified in Patent office? That 放在hearings 后面是什么意思，有什么作用？to test the system是表示后面这个colleague的目的嘛？。总觉得这个句子怪怪的，好难理解是什么意思？an observation.......physice是修饰one of laws的么？

请大家帮我分析一下，谢谢了。第一遍过OG中，好痛苦。。。

就算天空再深

to表示的就是colleage为了 test the exam 而 表目的 。

wyw1018

that引导宾语从句
简化语句就是 Richard.Stallman testified that
to test the system 在that宾语从句中做目的状语
an observation的理解的正确的