Traci Consumes Two Goods, Lemonade and Pretzels

Multiple Choice

Traci consumes two goods, lemonade and pretzels. Lemonade costs $2 per glass, and she consumes it to the point where the marginal utility she receives from her last glass of lemonade is 4. Pretzels cost $3 per bag. The relationship between the marginal utility Traci gets from eating a bag of pretzels and the number of bags she eats per month is as follows: If Traci is maximizing her utility, how many bags of pretzels does she buy each month?

A) 3
B) 4
C) 5
D) 6