a) How does the PPF illustrate scarcity?

b) How does the marginal benefit from a good change as the quantity produced of that good increases?

c) Why does the PPF bow outwards (i.e. concave) and what does this imply about the relationship between opportunity cost and quantity produced?

d) What does the slope of the PPF show?

e) How does the PPF illustrate productive efficiency? How does it illustrate allocative efficiency?

please help me by answering this question. Draw Graph if needed. ( Thanks in Advance )