A farmer can buy four types of plant food. Each barrel of mix A contains 20 pounds of phosphoric acid, 75 pounds of nitrogen, and 20 pounds of potash; each barrel of mix B contains 20 pounds of phosphoric acid, 100 pounds of nitrogen, and 30 pounds of potash; each barrel of mix C contains 20 pounds of phosphoric acid, 25 pounds of nitrogen, and 30 pounds of potash; and each barrel of mix D contains 40 pounds of phosphoric acid, 25 pounds of nitrogen, and 50 pounds of potash. Soil tests indicate that a particular field needs 620 pounds of phosphoric acid, 875 pounds of nitrogen, and 850 pounds of potash. How many barrels of each type of food should the farmer mix together to supply the necessary nutrients for the field? C Let x₁ be the number of barrels of Mix A, x₂ be the number of barrels of Mix B, x3 be the number of barrels of Mix C, and x4 be the number of barrels of Mix D. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. O A. The unique solution is x₁ = X2= , X3 = and X4 = (Simplify your answer.) X3 = and x4 = t for sts O B. There are multiple combinations of how the barrels should be filled. The combinations are obtained from the equations x₁ = , x₂ = (Simplify your answer. Type an expression using t as the variable.) O C. There is no solution.