Answer :
A. their
Their refers to the the multiple (both means more than one) squirrels themselves
If it was HIS then it would refer to only one squirrel
If it was OUR it would mean you and me (We) had our acorns hidden
Their refers to the the multiple (both means more than one) squirrels themselves
If it was HIS then it would refer to only one squirrel
If it was OUR it would mean you and me (We) had our acorns hidden
A: their (Both) of the squirrels had their pile of acorns hidden for winter. Say the sentence using all three words and you will see that the others sound silly out load! Try it!