The correct answer is C. feasible solution region.
The feasible solution region is the set of all points that satisfy all of the constraints in a linear programming problem. It is a convex set, meaning that any line segment connecting two points in the feasible solution region is also in the feasible solution region.
The non-negativity restrictions are a type of constraint that requires all of the variables in a linear programming problem to be non-negative. This means that the values of the variables cannot be negative.
The objective function is a mathematical expression that defines the goal of a linear programming problem. It is typically a linear function of the variables in the problem.
The constraints are the mathematical expressions that define the feasible solution region. They are typically linear inequalities or equations.
E is not the correct answer because it is not a valid option.