Suppose That Tracy Stuart Spends All of Her Income on Two

Suppose that Tracy Stuart spends all of her income on two goods, A and B, in a manner in which MU_a = 15 and MU_b = 80, and the P_a = $5 and the P_b = $20. Then she

A) is already maximizing her total utility and should make no change
B) should increase her purchases of B and decrease her purchases of A
C) should raise MU_a so that the MU_a/P_a ratio is higher, giving her reason to buy more of A and less of B
D) should raise MU_a so that the MU_a/P_a ratio is higher, giving her reason to buy more of B and less of A
E) should increase her purchases of A and decrease her purchases of B