OG-10-167题，麻烦NN给解释一下

167. Neanderthals had a vocal tract that resembled those of the apes and so were probably without language, a shortcoming that may explain why they were supplanted by our own species.

(A)  Neanderthals had a vocal tract that resembled those of the apes

(B)  Neanderthals had a vocal tract resembling an ape's

(C)  The vocal tracts of Neanderthals resembled an ape's

(D)  The Neanderthal's vocal tracts resembled the
    apes’

(E)   The vocal tracts of the Neanderthals resembled
    those of the apes

答案是B.但是我不太明白。尤其是题干中的so were probably without language,等表示什么意思？

是不是倒装啊？

Neanderthals  were so  probably without language, a shortcoming that may explain why they were supplanted by our own species.