求助一道语法

lololo

1998--08--12. _____________ that distinguish human beings from mother primates are related to the ability of people to stand upright and walk on two legs. (A) Many of the physical characteristics (B) Of the many physical characteristics (C) The physical characteristics (D) There are many physical characteristics 答案：A 选A没什么问题，但C为什么不对呢？A和C没什么本质区别啊？

ppp1

好像不是所有的物理特征都和the ability of people to stand upright and walk on two legs有关,所以应该加上many,不然意思太绝对了。不知道理解得对否？