Given the task definition and input, reply with output. You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: yes how about a moderate mexican restaurant? Sentence2: I'm not sure if I want to book yet or not, can you confirm the travel time for that one? Sentence3: Thanks that's all I need have a good day. Sentence4: Of course. TR1567 leaves at 17:29 and arrives at 18:07. Sentence5: Okay I have a 17:30 that arrives at 18:07. would you like me to book that for you? Sentence6: Italian would work just as good. Sentence7: I need it for Friday an I'm departing from Cambridge Sentence8: Can you direct me to a Catalan restaurant that is moderately priced please? Sentence9: I am also looking for a train going to Bishops Stortford that leaves after 15:30. Sentence10: The phone number is 01223324033. Sentence11: Okay great, have a good day! Sentence12: No, but could you give me the phone number for Pizza Express? Sentence13: Sorry, but there are no mexican restaurants in the price range either. Would you like to try a different type of restaurant? Sentence14: What day would you be traveling on? Sentence15: Unfortunately, I do not happen to have anything serving catalan food that is moderately priced. Would you like me to check a different cuisine type or price range? Sentence16: Italian is a wonderful choice. There is a pizza express in centre, would you like to make a reservation? Question: Who has spoken the sentence 13? (A) User (B) System
Answer: (B) System