You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: Sure, when were you looking to book for? Sentence2: I need to leave the restaurant by 22:15. I will need the contact number and car type as well please. Sentence3: the cambridge belfry is cheap, located in the west, and has 4 stars. It has free internet and parking. Sentence4: The car type is a white skoda and the contact number is 07572111702. Will that be all? Sentence5: What time would you like the taxi to arrive? Sentence6: What about the Cambridge Chop House? It is located in the centre of town and has expensive food. Sentence7: I'm departing from the cambridge belfry and heading to the cambridge chop house. Sentence8: The Cambridge Chop House serves British cuisine and is located at 1 Kings Parade with a postcode of cb21sj. Could I make a reservation for you? Sentence9: I'm looking for information on the cambridge belfry hotel. Sentence10: Please make a taxi reservation for me. Sentence11: You're welcome. Thank you very much for using our service. Sentence12: That is all, thank you. I got all the information that I need. Thank you and have a good day. Sentence13: I'd be happy to assist you, but I will need some more information. Where are you departing from and when would you like to leave? Sentence14: I'm sorry i don't need that booked. Rather i need information on a place to dine. Preferably expensive and in the centre of town. Sentence15: Sure that sounds great! Can you please give me their address, postcode and what type of food do they serve? Sentence16: Can you book that for me? Question: Who has spoken the sentence 1? (A) User (B) System
A: 
Answer: (B) System