You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: You're welcome. Is there anything else I can help you with? Sentence2: I am looking for a 3 star hotel to stay in. Sentence3: Thank you. What's the travel time? Sentence4: No, that is all I need. Thanks! Sentence5: I reserved Wednesday night at the University Arms Hotel for 5 people. Your reference number is GM90EY8A . Is there anything else? Sentence6: travel time is 47 minutes Sentence7: Lets try just booking it for one night. Sentence8: The hotel should be in the expensive price range. Sentence9: Okay, I've got two that fit the bill. One in the centre of town and one in the south. Do you have a preference? Sentence10: I am very sorry, but I was unable to book a reservation for you. Would you be willing to book a later day or would you be willing to have a shorter stay? Sentence11: I do, yes. I would like to stay in the center of town. I need it to fit five people, for 3 nights, starting Wednesday afternoon. Sentence12: Great! I will need 5 tickets. Sentence13: same day as my hotel booking. Sentence14: You are booked for Train Tr5556, your reference number is JA6WAOJC . Sentence15: I do have a four star hotel in the centre of town, but it is also unable to accommodate your guests for 3 days. Can you adjust your length of stay? Sentence16: Sure I will be able to book you a train, on what particular day will you want to travel? Sentence17: Can we book the other expensive 3 star hotel for one night starting on wednesday? Sentence18: I apologize. One night is not working either. There are guesthouses. Sentence19: How many tickets do you need? Sentence20: There are 6, 3 start hotels in Cambridge. Do you have a preference for the part of town it is located in? Sentence21: No trouble at all, I hope you have a wonderful stay! Sentence22: What about the 4 star hotels? Sentence23: Yes, I also need a train leaving after 18:30 from kings lynn to cambridge. Sentence24: Thank you very much. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User

Sentence1: Does it have four stars? Sentence2: Not yet, but can you tell me what time the train arrives in Ely please? Sentence3: acorn guest house is located in 154 chesterton road should i book it for you? Sentence4: I would like to leave on Tuesday after 18:00. Sentence5: It arrives by 20:07! Anything else love? Sentence6: TR5511 leaves Cambridge for Ely at 20.07. Do you need tickets? Sentence7: I've booked your stay at the Acorn Guest House, and your reference number is IT07BRTC . Sentence8: The trip will last 17 minutes. Is there anything else you would like to know? Sentence9: Do you know what day or time you want to leave? Sentence10: Thank you for using Cambridge TownInfo centre. Please consider us for your future travel needs. Sentence11: I need some lodging accommodations. It needs to have free parking and Internet please! Sentence12: I would like someone to book me a place with free parking and internet. Sentence13: That should do it. Thanks so much for your help! Sentence14: I found 29 hotels matching your request. What price range and area of town would you prefer? Sentence15: Thanks a lot. Can you also help me find a train going to Ely? Sentence16: Yes. Please book it for 2 people for 4 nights starting Friday. Sentence17: Yes it does. Shall I book? Sentence18: What is the total travel time on that time? Question: Who has spoken the sentence 15? (A) User (B) System
Answer: (B) System

Sentence1: Is there a 4 star guesthouse in the north that is in the moderate price range instead? Sentence2: There are seven of them. I can recommend the archway house if you would like It has free internet and parking. Sentence3: I need one in the north and a guesthouse. Sentence4: to what destination? there is one to London Liverpool street arriving at 09:27, will that do? Sentence5: I am looking for an expensive 4 star hotel. Sentence6: Hold on, is there any trains leaving Cambridge that arrives by 11:30? Sentence7: You're welcome. Have a good day. Sentence8: Oh great thanks, that's all I needed! Sentence9: I have 2 options for expensive hotels. One at kingfisher way, huntingdon. The other is at regent street. Would you like to consider one of these? Sentence10: There are no guesthouses in the north that meet your criteria. Can I check for hotels or another area perhaps? Question: Who has spoken the sentence 7? (A) User (B) System

Answer: (B) System