．By no means true that all English people know their own lan

选C吧.
By no means / in no case / at no time / in no way等表示“绝不”的短语位于句首时要部分倒装,is提前.

it能做形式主语,代“that all English people know their own language well”,that则不能.


原句：That all English people know their own language well is by no means true.
句意：所有英国人熟知他们的语言是绝不正确(可能)的.

c完全倒装

你的空是在哪里呢。。如果是在开头的话，感觉应该是选D
It is ...that ...句型。that 后面才是真正的主语，即all English people know their own language well