Betty Spends All Her Income on Cheese and Crackers

Betty spends all her income on cheese and crackers.She finds that the marginal utility of cheese is 10 and the marginal utility of crackers is 15.The price of cheese is $5 per unit,and the price of crackers is $3 per unit.At this point,Betty:

A) is maximizing her utility subject to her budget constraint.
B) should consume more cheese and fewer crackers.
C) should consume more crackers and less cheese.
D) should consume more crackers and more cheese.
E) should switch her consumption over to other goods that she likes better.