Concept:The law of supply focuses on the effect of price changes on the amount producers are willing to sell.
Explanation:Holding all other factors constant, a rise in price creates a higher incentive for producers to sell more.
Therefore, as price increases, the quantity supplied moves in the same direction.
This is a movement along the supply curve, not a shift of the whole supply curve.
So the correct description is "quantity supplied increases", not simply "supply increases".
Answer:C. Quantity supplied increases