Solve the linear programming problem using the simplex method. Maximize subject to ​P=4x1​+2x2​−x3​x1​+x2​−x3​≤62x1​+4x2​+3x3​≤18x1​,x2​,x3​≥0​ Use the simplex method to solve the problem. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. A. The maximum value of P is when x1​=,x2​= and x3​= (Simplify your answers. Type integers or decimals rounded to the nearest tenth as needed.) B. There is no optimal solution.