Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
B - "had had" - I know there are cases when this construct could be right, however, don't think it is needed here.
C- changes meaning - it is comparing the current campaign to all the previous missons that may or may not have included russia - not sure if this was the intended meaning, so sticking with the original meaning
D - incorrect comparison - compares "more supplies" to "previous campaign"
I agree with you guys, "their" and "they" are incorrect pronouns since army is singular.
My concern with E was that it was incorrectly comparing supplies with the previous campaign... I guess.. the "for" in "for any previous campaign" is used to indicate the supplies and hence makes the right comparison.