Concept:For a linear programming problem, the maximum value of a linear objective function under linear constraints occurs at one of the corner points of the feasible region.Explanation:The objective function is z=4x+y.The feasible region is bounded by the constraints:x+y≤5,2x+y≤7,3x+2y≤11,x≥0,y≥0.Find the corner points by solving the boundary equations pairwise and checking feasibility.The feasible corner points are:(0,0),(27,0),(3,1),(1,4),(0,5).Now evaluate z=4x+y at each corner point.At (0,0): z=4(0)+0=0.At (27,0): z=4(27)+0=14.At (3,1): z=4(3)+1=13.At (1,4): z=4(1)+4=8.At (0,5): z=4(0)+5=5.The largest value is 14, achieved at (27,0).Answer:The maximum value is 14, so the correct option is D.