Delta Company makes as well as sells table saws which are designed to be safe if used properly. Erin buys a Delta saw as well as lends it to her neighbour Frank. To reach a toolbox on a high shelf in his garage Frank props the saw at an angle against a cabinet as well as climbs onto the saw. Frank loses his footing, slips off the saw, falls on the blade and is injured. He records a product liability suit against Delta on the ground of negligence. On what basis could Delta prevail?