Answer Happy

Which of the following statements is true? (3 marks) (a) If a firm's production possibility frontier is concave, then it must face decreasing opportunity costs and increasing returns. (b) If a firm's production possibility frontier is convex, then it must face decreasing opportunity costs and decreasing returns. (c) If a firm's production possibility frontier is concave, then it must face increasing opportunity costs and decreasing returns. (d) If a firm's production possibility frontier is linear, then it must face increasing opportunity costs and constant returns.