Straight line
Convex
Backward leading
Concave
✅ The correct answer is A.
If the marginal (additional) opportunity cost is a constant then the PPC would be Straight line. Ppc constant means goods are perfect substitute if they are perfect substitute then that curve is a straight line
If the marginal (additional) opportunity cost is a constant then the PPC would be Straight line. Ppc constant means goods are perfect substitute if they are perfect substitute then that curve is a straight line