Answer: Option C
Explanation: Perfect competition refers to a market structure under which there are large number of buyers and sellers each operating at a small level.
In such a market structure the supply curve is a horizontal line that depicts that whatever the quantity is the price will remain the same, that is, at the equilibrium level.
This happens due to the fact that there are large of number of participants present and no individual have the power to affect the price.
Thus, the correct option is C.