Suppose that Ms. Thomson is currently exhausting her money income by purchasing 10 units of A and 8 units of B at prices of $3 and $9, respectively. The marginal utility of the last units of A and B are 15 and 18, respectively. These data suggest that Ms. Thomson Multiple Choice has preferences that are at odds with the principle of diminishing marginal utility. considers A and B to be complementary goods. should buy less A and more B. should buy less B and more A.