Find the optimal solution to the given problem: A farmer can buy three types of plant food, mix A, mix B, and mix C. Each cubic yard of mix A contains 20 pounds of phosphoric acid, 10 pounds of nitrogen, and 10 pounds of potash. Each cubic yard of mix B contains 10 pounds of phosphoric acid, 10 pounds of nitrogen, and 15 pounds of potash. Each cubic yard of mix C contains 20 pounds of phosphoric acid, 20 pounds of nitrogen, and 5 pounds of potash. The minimum monthly requirements are 480 pounds of phosphoric acid, 320 pounds of nitrogen, and 225 pounds of potash. If mix A costs $30 per cubic yard, mix B costs $36 per cubic yard, and mix C costs $39 per cubic yard, how many cubic yards of each mix should the farmer blend to meet the minimum monthly requirements at a minimal cost? What is the minimum cost? answer choices: a. mix A = 1.05 cubic yards, mix B = 0.9 cubic yards, mix C = 16.5 cubic yards, Cost = $63.90; b. mix A = 0.06 cubic yards, mix B = 1.56 cubic yards, mix C = 1.32 cubic yards, Cost = $109.44; c. mix A = 16 cubic yards, mix B = 2 cubic yards, mix C = 7 cubic yards, Cost = $825; d. none of the above Solution c.