What are the critical points for the following problem? A farmer is mixing two types of food, Brand A and Brand B, for her pigs. Each serving is required to have 60 grams of protein and 30 grams of fat. Brand A has 15 grams of protein and 10 grams of fat and costs $0.80 per unit. Brand B contains 20 grams of protein and 5 grams of fat and costs $0.50 per unit. How much of each type should be used to minimize cost to the farmer? What is the minimum cost? O (4,0), (1,2), (0,6) O (0,6) , (2.4, 1.2), (4,0) O (0,3), .4, 1.2), (3,0) O (0, 4), (1, 2) , (4,0)