Keith sees a food vendor and realizes that he is hungry. he has $7 cash in his pocket. look at the menu and determine which of these food orders would cause keith to spend all the cash in his pocket? a) 2 hamburgers b) 1 hamburger, 1 ice cream c) 1 hamburger, 1 order of fries d) 1 hamburger, 1 order of fries, 1 soft drink