【单选题】Grace maximizes her utility by consuming both gourmet cookies and ice cream. If the price of a dozen cookies is three times that of a pint of ice cream, we would expect that:
A.
the total utility of a dozen cookies is three times that of a pint of ice cream.
B.
the total utility of a dozen cookies is one-third that of a pint of ice cream.
C.
the marginal utility of the last dozen cookies is three times that of the last pint of ice cream.
D.
the marginal utility of the last dozen cookies is one-third times that of the last pint of ice cream.