Isaac's preferences are characterised by a utility function. There are two goods, bread and eggs. Eggs cost $5 (per dozen) and bread costs $3 (per loaf). Isaac currently buys positive amounts of both goods, and for the bundle he buys, his marginal utility of eggs is 7, his marginal utility of bread is 5, and he spends all of his income. Which of the following is true? (Assume that both goods are continuous.)

Select one:

a.

Isaac is spending his income optimally.

b.

Isaac should buy less bread and more eggs.

c.

Isaac should buy more bread and fewer eggs.

CORRECT ANS : C

Question : Why is it C?