Read the following fable called, “the fox and the grapes” and answer the question that follows.

one hot summer’s day, a fox was strolling through an orchard
till he came to a bunch of grapes just ripening on a vine, which
had been trained over a lofty branch. “just the thing to quench
my thirst,” quoth he. drawing back a few paces, he took a run and
a jump and just missed the bunch. turning round again with a
one, two, three, he jumped up, but with no greater success. again
and again he tried after the tempting morsel, but at last, he had to
give it up and walk away with his nose in the air, saying, “i
am sure they are sour.”

which of the following best explains why the fox walks away at the end?
a. he does this because he realizes that the grapes are sour.
b. he does this because it is hard to admit failure. it is much easier to say it wasn’t worth the time.
c. he does this because he gets tired and knows the grapes are not worth the effort.
d. he does this because he is frustrated and realizes that they are not worth his time.