In a restaurant, all the dishes belong to Sichuan cuisine or Cantonese cuisine, and Mr. Zhang's order includes Sichuan cuisine. Therefore, there is no Cantonese cuisine in Mr. Zhang's order. Which of the following is necessary to make the above argument valid? ['The restaurant stipulates that when you order Cantonese food, you cannot order Sichuan food and vice versa.', 'The restaurant rules that if you order Sichuan food, you can not order Cantonese food, but when you order Cantonese food, you must also order Sichuan food.', 'Mr. Zhang is from Sichuan and only likes Sichuan cuisine.', 'Mr. Zhang is a Cantonese, and he likes Cantonese food.']