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

Sentence1: Great. I was finally able to get you into the Autumn House staring Friday for 3 nights and 3 people. your booking reference is C5ARPTZ2 . Sentence2: Sorry about the confusion earlier. I was able to book your room at Leverton House for Friday, 3 nights for 3 people. The reference number is U5B3PHWC . Sentence3: It was my pleasure. Goodbye! Sentence4: Can you try 3 nights instead? Sentence5: Perfect. I would like to book it for 3 people for 4 nights starting on Friday. Sentence6: Awesome. Thank you for everything! Sentence7: I can help you with a taxi. Please tell me your departure and destination sites along with your time frame. Sentence8: Yes let's try a different hotel. Sentence9: How about Cambridge Contemporary Art, on 6 Trinity St? Entrance is free. Sentence10: The Leverton House is a guesthouse located on the east side of Cambridge. What information are looking for? Sentence11: Both of them are booked solid for the days you requested. Would you like a hotel in a moderate price? Sentence12: I'd like to visit a museum if possible. Sentence13: Can they accommodate 3 people for 4 nights? Also, what are their phone numbers? Sentence14: I'm sorry. I am unable to book your stay. Could you arrive on another day or stay for a shorter amount of time? Sentence15: I'm sorry, it doesn't look like the Leverton House will be able to accommodate you. How about Allenbell or Autumn House? They are in the same area and also inexpensive. Sentence16: Can you please check for 3 nights at the same hotel for 3 people and can I have the reference number? Sentence17: I'm sorry both of those hotels are booked solid. Would you consider slightly more expensive accommodations? Sentence18: Okay. I'll need a taxi too. Sentence19: I want to leave the hotel by 22:00 to go to the Museum you mentioned. Sentence20: I'm looking for places to go in the centre of town. Sentence21: I'm also going to need a taxi, please. Sentence22: Sure. But I still need to book a hotel. Is there anything else available? Sentence23: Do you have the phone number for Autumn House's front desk? Sentence24: There are many attractions in the centre of town. Could you be more specific about what you're looking for? Sentence25: I'm looking for information on the Leverton House hotel. Sentence26: Sure. It's 01223575122. Anything else? Sentence27: They don't have a room available for 3 nights either. Anything else you'd like me to try? Sentence28: A black skoda will pick up up at Leverton House at 22:00 and bring you to Cambridge Contemporary Art Museum. The contact number is 07697068185. Question: Who has spoken the sentence 15? (A) User (B) System
Answer: (B) System

Sentence1: I have 23 places. What area would you prefer to be in? Sentence2: There is Cafe Jello Gallery in the west, Cambridge Artworks in the east and Broughton House Gallery in the centre. Does any of those sound appealing? Sentence3: Just the price range and postal code please. Sentence4: Cafe jello gallery postcode is cb30af and the entrance is free, is there anything else I can do for you? Sentence5: Here is the address 529 Newmarket Road Fen Ditton. Sentence6: Do you have an attraction type preference? Sentence7: You're welcome! Enjoy your visit! Sentence8: that is it. thank you for helping me Sentence9: Yes, I would like to see a museum. Can you tell me the postcode and entrance fee for it? Sentence10: I have no particular area preference. Can you list a few for me to select from? Sentence11: Yes could I have their postcode and entrance fee? Sentence12: Can you give me more information about Yu Garden. Sentence13: Of course! It is a chinese cuisine restaurant located in the east. Anything else you would like to know? Sentence14: I am traveling to Cambridge and excited about seeing local tourist attractions, can you help? Sentence15: I am also looking for the restaurant Yu Garden. Sentence16: Their price range is expensive and the postcode is cb58pa. Are you sure that is all you needed? Question: Who has spoken the sentence 13? (A) User (B) System
Answer: (B) System

Sentence1: Thank you for using our system. Good bye Sentence2: Golden Wok is located 191 Histon Road Chesterton at and their postcode is C.B 4, 3 H.L. Is there anything else I can help you with today? Sentence3: Thank you goodbye. Sentence4: I am looking for a moderately priced chinese restaurant. Sentence5: Golden wok is moderately priced restaurant located in the north part of town. Sentence6: Could you please give me their address and postcode? Question: Who has spoken the sentence 3? (A) User (B) System

Answer: (B) System