from which 后面的部分要倒置?

prep 破解上的题目:

The Achaemenid empire of Persia reached the Indus Valley in the fifth century B.C., bringing
the Aramaic script with it, from which was derived both northern and southern Indian alphabets.
(A) the Aramaic script with it, from which was derived both northern and
(B) the Aramaic script with it, and from which deriving both the northern and the
(C) with it the Aramaic script, from which derive both the northern and the
(D) with it the Aramaic script, from which derives both northern and
(E) with it the Aramaic script, and deriving from it both the northern and 

正确答案是C.因为根据倒置结构derive要是复数形式.

为什么这里from which后面的部分需要倒置呢?看到很多类似结构,如in which,引导的从句都没有倒置.

介词短语放在句首是要完全倒装的.这里相当于放在从句句首。

表示地点的介词短语位于句首时。如：
    Between the two buildings stands a tall pine.两座楼之间有棵大松树。
    Along the dusty road came a great many tourists.沿着尘土飞扬的道路来了许多游客。

有时为了强调或者为了使句子平衡或者为了使上下文连接得更加紧密，就将表语和地点状语(多为介词短语)置于句首，谓语动词也常置于主语前，构成完全倒装。如：
By the door stood an armed guard. 门口站着一名手持武器的士兵。
At the next table was a pretty girl waiting for someone. 隔壁桌上坐着一个等人的漂亮姑娘。
Among these people was his friend Jim. 他的朋友吉姆就在这些人当中。
By the window sat a young man with a magazine in his hand. 窗户边坐着一个年轻人，手里拿着一本杂志。
At the front of the book is a table of contents, giving details of what is in the book. 书的前部有目录，详列了书中的内容。

另外，谓语动词必须是不及物动词。主语不能是代词(必须是新信息)。

可是介词+which这样的我们以前遇到的都没有倒装啊？是不是倒装不倒装都可以？

另外，从句句首也算是句首么？？

谢谢

多谢版主.

to 楼上:

from which在从句中的作用貌似就跟介词片语等同.用版主的解释能说得过去吧?