Success often depended on the ____ food suply.

Is it
A. armies
B. armie's
C. armys'
D. army's
I say it is d. army's

Right! :-)

Go to the head of the class, you are right.

To determine the correct answer, we need to understand the concept of possessive nouns. In this sentence, we are referring to the food supply that belongs to the army. Hence, we need to use the possessive form of "army."

Now let's analyze each option:

A. armies - This is the plural form of "army" and does not indicate possession.
B. armie's - This form is incorrect because "armie" is not a recognized word.
C. armys' - This form is also incorrect because it does not use the correct apostrophe placement.
D. army's - This is the correct form as "army's" indicates possession, showing that the food supply belongs to the army.

So, you are correct! The answer is D. army's.