Assume That the Marginal Utility of the Third Candy Bar

Assume that the marginal utility of the third candy bar is 15,the marginal utility of the first tube of toothpaste is 12,the price of a candy bar is $1.50 per bar and the price of toothpaste is $2.00 per tube.If Tom buys three candy bars and one tube of toothpaste,is he applying the rational spending rule correctly?

A) Yes,this is an optimal combination of candy and toothpaste.
B) No,he should spend less on candy and more on toothpaste.
C) No,he should spend more on candy and less on toothpaste.
D) No,he should spend more on both candy and toothpaste.
E) No,he should spend less on both candy and toothpaste.