An outbreak of gastritis occurred on a cruise ship.The data below were obtained shortly after the outbreak, from a questionnaire completed by everyone on board the ship. What is the most likely infective food on the cruise ship?

	People who ate Food	People who did not Eat
Food	Sick	Well	Sick	Well
Herring	200	800	100	900
Chicken	650	350	100	900
Spinach Souffle	200	800	500	500
Oysters	300	700	400	600
Chocolate Mousse	600	400	450	550

		herring
		chicken
		spinach souffle
		oysters
		chocolae mousse