Figure 3.3.1 Good Y 80 70 60 50 40 30 20 10 0 1 2 3 4 5 6 7 8 9 Good X The economy is at point a on the PPF in Figure 3.3.1. The opportunity cost of moving to point b is O A. 50 units of Y. O B. 2 units of X. O C. 30 units of Y. O D. 6 units of X