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

[EX Q]: 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
[EX A]: Answer: (B) System

[EX Q]: Sentence1: I hear its a pretty cool place. Can I get their postcode please? Sentence2: Yeah, I need a place to stay on the south side. 4 stars if possible. Sentence3: Postal is cb17sr, they do include internet and they can be reached at 01223240089, can I help with anything else? Sentence4: i am looking for a particular attraction. Its name is called soul tree nightclub. Sentence5: You're welcome! Have a great day! Sentence6: Can you book me a stay at The Aylesbray Lodge? Sentence7: The Soul Tree Nightclub is located in the area of centre. It has an entrance fee of 4 pounds. The phone number is 01223477900. Anything else? Sentence8: The postcode is cb23qf. Do you need anything else? Sentence9: You have a great day as well! Sentence10: Thanks for using our services. Sentence11: Sure! How many are staying, how many days, and what day do you want the stay to start? Sentence12: That was everything, thanks a lot! Sentence13: No I just need the postcode, phone # and if they have internet Sentence14: We have two guesthouses that are 4 stars in the south end, The Aylesbray Lodge Guest House is moderately priced, and Rosa's Bed and Breakfast is in the cheap range. Question: Who has spoken the sentence 12? (A) User (B) System
[EX A]: Answer: (A) User

[EX Q]: Sentence1: Yes. Please give me the entrance fee, address, and phone number for The Sheep's Green, please. Sentence2: You're welcome, let me know if I can assist with anything else. Sentence3: please do the booking for me..two persons Sentence4: I would prefer the south side of Cambridge. Sentence5: We have an expensive 2 star hotel in the east called express by holiday inn cambridge. It's located at 15-17 norman way, coldhams business park. Do you need a reservation? Sentence6: Just me, thank you. Sentence7: I need to leave the attraction by 11:30. Sentence8: Do they have free parking? Sentence9: How many people will be traveling? Sentence10: Is there a particular area of town you'd like to spend time in? Sentence11: I can do that. I just need to know what time you want to leave or arrive? Sentence12: Thank you, that is all I need for to today. Sentence13: I am looking for a park to go to. Sentence14: I have two parks in the south. The Sheep's Green and Lammas land park fen causeway and the other is Wandlebury Country park. Would you like info on either one? Sentence15: No problem! A red Ford will pick you up from the park, contact number 07109413810. Can I help with anything else? Sentence16: Sorry, don't want to book right now. But I do need a taxi to get between the attraction and the hotel. Sentence17: Thank you. I'm also look for an expensive hotel, not a guesthouse, to stay in. I'd like it to have free wifi and it needs to have 2 stars. Sentence18: Yes they have free parking as well as free wifi. Sentence19: When will you arrive and how many days will you be staying? Sentence20: the phone number is 01223302580 and admission is free Question: Who has spoken the sentence 15? (A) User (B) System
[EX A]:
Answer: (B) System