Question

read this part from the selection. the phrase \a real purpose\ means the cow is
a expensive.
b for sale.
c useful.
d old.
but your cow is an animal with a real purpose.
if i had a cow, i would have milk, butter, and cheese
every day.

Explanation:

The text mentions having milk, butter, and cheese every day if there is a cow. These are useful products. So "a real purpose" implies being useful.

Answer:

C. useful