44- David spends all his budget to buy 3 tacos and one soda. Taco is $2 each and soda is $1.50 each. If marginal utility of soda is 15 and marginal utility of 3rd taco is 20, David a) is not maximizing his utility b) is maximizing his utility. c) is buying too many tacos d) is consuming on the y-intercept of his budget line.