Alvin Chipmunk owns a condominium in South Carolina. The floodlights at the bottom of the stairs to the front of the unit were not working. He put a sign up on the banister next to the staircase, advising people to use the back door of the condominium until the floodlights could be fixed. Before Alvin could fix the floodlights, he had a bunch of friends over to watch a football game and ordered 10 pizzas from Dominoe's Pizza. Peter Pizzaboy, the pizza delivery boy who delivered the 10 pizzas to Davenport's condominium, did not see the sign because of the 10 pizzas he was carrying. He fell and injured himself as he was climbing the stairs. South Carolina is a mixed comparative negligence state. Pizzaboy wants to sue Alvin. If Alvin is found to be 40% liable for the injuries suffered by Peter Pizzaboy, what defense would Alvin Chipmunk present to reduce or eliminate Peter Pizzaboy's claim for damages? Please explain your answer.