On this graph, the top horizontal line represents?
a price floor set above equilibrium.
a price floor set below equilibrium.
a price ceiling set above equilibrium.
a price ceiling set below equilibrium.

a price floor set above equilibrium

Explanation:

A price floor is a concept to prevent prices from being too low. Generally, it is used by governments to prevent the rights of supplier and sellers. A horizontal line above the equilibrium depicts price floor.  Usually, if a price is set above the equilibrium, excess supply or surplus of commodities take place which results in a decrease in the prices. This is why the price floor is normally set at equilibrium.

answer; the coefficient of determination;