The feasible region in the graphical solution will be surrounded by how many lines?

Question

If m is the number of constraints in a linear programming with two variables x and y and non-negativity constraints x > 0, y > 0; the feasible region in the graphical solution will be surrounded by how many lines?

(a) m                   (b) m + 1    

(c) m + 2             (d) m + 4