Late one evening, a cook at a diner coming off his shift was grabbed in the parking lot by a large man wearing a ski mask. the man threatened to kill the cook and demanded his wallet. the man then pulled a knife from his pocket and lunged at the cook. the cook, having taken several self-defense courses, was able to fend off the man’s attack. after being struck by the cook several times, the man dropped the knife and fell to the ground. the cook, angry at the assault, took the knife and stabbed the man, killing him instantly. should the cook be convicted of murder?