Almost like clones in their similarity to one another,
the cheetah species’ homogeneity makes them especially vulnerable to disease.
A. the cheetah species’ homogeneity makes them especially vulnerable to disease
--> "homogeneity" is wrongly compared to "clones" . We can say that one clone is smiliar to another clone. However, can we say that a homogeneity is similar to another homogeneity? ---> It is obviously that "homogeneity" can't be compared with "clones" . Also, "them" has no specific antecedent.
One gramma point noted by Vivek123 long ago:
1. The taciturn personality of
Joana makes
her difficult to approach. --> in this case, "her" is understood to refer to "Joana"
In another case:
2. Joana's taciturn personality makes her difficult to approach --> "her" cannot be used to refer to "Joana"
==> for above reasons, A is out.
B. the cheetah species is especially vulnerable to disease because of its homogeneity
--> "its" has no specific antecedent, whether it's "species" or "disease" we don't know. --> B is out.
C. the homogeneity of the cheetah species makes it especially vulnerable to disease
---> "homogeneity" is wrongly compared with "clones"
--> C is out.
D. homogeneity makes members of the cheetah species especially vulnerable to disease
---> Same reason as in C. --> out
E. members of the cheetah species are especially vulnerable to disease because of their homogeneity --> correct.