Discussion

   A bite from the tsetse fly invariably paralyzes its victims unless an antidote is administered within two hours.
(A)    its victims unless an antidote is administered
(B)...
(C)...
(D)...
(E)...
(F)...
*This question is included in Nova Writing Drills: Warm-Up Drill I, question #6

The solution is

Posted: 09/05/2013 22:22
"twohours" should be TWO WORDS!
Posted: 10/07/2013 17:46
Thank you for noticing, Kelli. It will be fixed in the next update.
Image Not Available
Posted: 06/22/2014 17:06
How come "they" identifies the victims and not the flies?
Posted: 06/23/2014 15:53
DP, because in the sentence, the pronouns are "the tsetse fly" and "its victims". Note the singular and plural forms.