大全286，its的指代

Even today, a century after Pasteur developed the first vaccine, rabies almost always kills its victims unless inoculated in the earliest stages of the disease.

(A) its victims unless inoculated

(B) its victims unless they are inoculated

(C) its victims unless inoculation is done

(D) the victims unless there is an inoculation（B）

(E) the victims unless inoculated

A,B,C中的its指代什么？

谢谢！

晕，我一直以为它是复数，所以一上来就吧its的选项都咔嚓了。

谢谢呀。