$($Figure: Production Possibilities$)$ Which statement is NOT correct regarding point X$?$

Question $9$ options:

a$)$

Because it is on the line, the combination at point X has no opportunity cost.

b$)$

Society might prefer other combinations on the line to the mix of output at point X$.$

c$)$

The combination produced at point X is productively efficient.

d$)$

Suppose in the market for iPhones, the following two changes take place: $(1)$ the cost of making iPhones rises, and $(2)$ customers begin to prefer Android$-$platform smartphones over iPhones. What happens to equilibrium price and equilibrium quantity?

Question $10$ options:

a$)$

The equilibrium price falls, but the equilibrium quantity is indeterminate.

b$)$

The equilibrium price rises, but the equilibrium quantity is indeterminate.

c$)$

The equilibrium price and the equilibrium quantity fall.

d$)$

The equilibrium price is indeterminate, but the equilibrium quantity falls.