Despite the fact that the health-inspection procedures for catering establishments are more stringent than those for ordinary restaurants, more of the cases of food poisoning reported to the city health department were brought on by banquets served by catering services than were brought on by restaurant meals.
Which of the following, if true, helps explain the apparent paradox in the statement above ？（）
A．A significantly larger number of people eat in restaurants than attend catered banquets in any given time period.
B．Catering establishments know how many people they expect to serve, and therefore are less likely than restaurants to have, and serve, leftover food, a major source of food poisoning.
C．Many restaurants provide catering services for banquets in addition to serving individual meals.
D．The number of reported food-poisoning cases at catered banquets is unrelated to whether the meal is served on the caterer’s or the client’s premises.
E．People are unlikely to make a connection between a meal they have eaten and a subsequent illness unless the illness strikes a group who are in communication with one another.