You need to buy peanut butter. You have a 40¢ off coupon for Creemy Peanut Butter. The coupon can be used on one 40 oz. jar, one 28 oz. jar, two 18 oz. jars, or two 12 oz. jars. The prices for Creemy Peanut Butter are 12 oz. jar $2.85 18 oz. jar $3.49 28 oz. jar $5.15 40 oz. jar $6.29 The best buy is

a. One 40 oz. jar
b. One 28 oz. jar
c. Two 18 oz. jars
d. Two 12 oz. jars