You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: 5 people for the train please. Sentence2: The fitzbillies restaurant is in the town center and it meets what you are looking for. Would you like for me to make you a reservation? Sentence3: Yes I am also looking for a restaurant in the centre of town in the expensive price range. Sentence4: Have a great trip! Sentence5: That's all, thank you. Sentence6: Perfect, can you book it for 5 people on the same day at 16:30? Sentence7: Are you certain you don't need further assistance? Sentence8: Great I have booked your tickets for 5 people leaving at 21:40 and arriving at 22:08. Is there anything else I can help you with? Sentence9: Can we try for 15:30? I also need the reference number for the train booking. Sentence10: There are several departures to Stansted Airport with one every hour beginning at 22:08. Would you like for me to look up a local restaurant for you? Sentence11: How many tickets shall I book for you on the 22:08 train on Friday from Cambridge to Stansted Airport? Sentence12: I need a train to stansted airport that leaves after 21:30. I am also going to be looking for local places to eat. Sentence13: Sorry, but they're all full at that time. Would you like to try a different time or perhaps another day? Sentence14: Your reference number for the train is KVNAC7LA . I was able to book Fitzbillies for you at 15:30. Your reference number for the restaurant is UN2K2CD8 . Is there anything else? Sentence15: I will take a seat on the 22:08 departure as long as it departs from Cambridge on Friday. Yes, please find a restaurant. Sentence16: Yes, I'm sure. Thanks. Question: Who has spoken the sentence 5? (A) User (B) System
A:
Answer: (B) System