Zendaya consumes both salad (x) and pizza (y) with utility given by U(x,y) = 20x1/2y. In January she consumes (x,y) = (9,3) for salad and pizza, respectively. If in February she consumes 4 salads, how many total pizzas must she consume to be indifferent between January and February? 0 8 0 3 O 4.5 O 2 O 6.5