I didn't even know the rules of the game,much ___what i was

I didn't even know the rules of the game,much ___what i was doing.
(A) less (B) later (C) worse (D) further?
答案是(A) less.
为什么呢?
Much less 是连词,也是英语成语,有and certainly not 或 not to mention 之意.看下面一些例子：
Happiness is an emotion not often spoken of at the magazine,much less experienced.
After spraining his ankle,the gymnast hadn't been expected to appear in today's event,much less win it.

这句话的意思是：我甚至不知道这个游戏的规则，比我所玩过的部分还少