Sentence Correction

Reticulated pythons number among a thousand or so species of the world's poisonous snakes, snakes living in a highly scattered and unorganized community where they consist mostly of females and infants.

(A)
snakes living in a highly scattered and unorganized community where they consist mostly of

(B)
snakes that live in a highly scattered and unorganized community consisting mostly of

(C)
which means they live in a highly scattered and unorganized community, mostly of

(D)
which means that their community is highly scattered, unorganized, and it is consisting mostly of

(E)
living in a community that is highly scattered, unorganized, and it consists mostly of

Nice question.

(A) snakes living in a highly scattered and unorganized community where they consist mostly of - The pronoun "they" does not make sense in this sentence. If we replace "they" with snakes, the sentence becomes - "snakes living in a highly scattered and unorganized community where snakes consist mostly of females and infants." This doesn't make sense as the snakes do not consist of females and infants; the community consists of females and infants

(C) and (D) - using "which" for the subordinate clause changes the meaning of the sentence. The fact that python is among the world's poisonous snakes doesn't mean that it belongs to a certain community. Also, "which" is used to describe the noun closest to it and so it makes no sense to use "which" here.

(E) Parallelism error - "it consist mostly of" is not parallel to "scattered" and "unorganized".

(B) is correct in my opinion as there is no grammatical error and the sentence structure brings out the meaning clearly.