Suppose a consumer spends all his income. His marginal utility per dollar on X is 4 and marginal utility per dollar on Y is 2. We know that

A. utility can be increased by increasing the consumption of X and decreasing the consumption of Y.

B. utility can be increased by decreasing the consumption of X and increasing the consumption of Y.

C. the price of Y must be eight times the price of X.

D. the price of Y must be one minus third the price of X.

E. utility is maximized.