41. If a country has a straight (downward sloping) production possibilities frontier, then production is said to be subject to
A. first increasing and then decreasing opportunity costs.
B. decreasing opportunity costs
C. increasing opportunity costs.
D. constant opportunity costs.
D. Constant opportunity cost.
Nb: The slope of Production possibility curve is Marginal Opportunity cost / Marginal rate of transformation.When Marginal opportunity cost is constant then production possibility curve becomes a downward sloping straight line.