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

[EX Q]: Sentence1: Phone is 01223505015 and postcode cb11ln. Would you like me to get you a table? Sentence2: No that's all. Thanks so much! Sentence3: I booked you on TR8399 arriving at 10:07. Booking was successful, the total fee is 17.6 GBP payable at the station . Reference number is : AVBKNMXQ . Sentence4: Thank you very much. Sentence5: I'm looking for an expensive restaurant that serves european food while I'm in Cambridge. Sentence6: Darry's Cookhouse and Wine Shop is located at 40270 King Street at the City Centre. Would you like their phone number? Sentence7: Yes, please, and their postcode as well. Sentence8: You are welcome. Enjoy your stay. Sentence9: No. But I need a train going to Ely. Sentence10: Where are you travelling from and what time? Sentence11: I am departing from cambridge on monday and I need to arrive to Ely by 11:15. Sentence12: You choose one please. I need it for 4 people. Sentence13: Is there anything else I can help you with? Sentence14: I have 3 trains available leaving at 06:07, 08:07, and 10:07. What time would you like to leave? Question: Who has spoken the sentence 6? (A) User (B) System
[EX A]: Answer: (A) User

[EX Q]: Sentence1: Booking was successful for Tuesday. Your Reference number is : 0J3V1091 . Sentence2: I'm sorry that doesn't seem to be available would you like me to try a different day or guesthouse? Sentence3: I'm sorry, there does not seem to be a historical site or hiking area in Cambridge. Is there anything else I can help with? Sentence4: Sure, I can help you with that. What section of town were you looking for? Sentence5: Doesn't really matter if they offer either of those or not. I just want it to be a 0 star hotel. Sentence6: Then the city centre north b and b is what you want, shall I book you? Sentence7: i don't really care about the area. Sentence8: I want to see local sights, can you help? Sentence9: I like hiking and seeing historical sites. Sentence10: Okay. Are you interested in hotels that offer internet and/or parking? Sentence11: Yes, I would like to find a hotel in the cheap price range? Sentence12: Yes, a guesthouse is fine. I was looking for zero stars and in the cheap price range. Sentence13: Great, thanks. I don't need anymore help. Goodbye! Sentence14: Yes, please book it for me. Sentence15: I'm sorry, I seem to be having an error in my system. You want a booking at the citycentre north B&B for 6 people, 5 nights, on Monday? Sentence16: I'm also looking for somewhere to go. Perhaps the college. Can you tell me the postcode for the college? Sentence17: City Cenrtree North and B is a cheap hotel,would you like me to book it for you ? Sentence18: Let book the same but on Tuesday instead. Sentence19: I'm happy I could help today. Goodbye! Sentence20: There are 18 colleges in town. I recommend christ's college in the centre. The postcode is cb23bu. Sentence21: Yes, there is a wide variety, do you have an activity type that your are interested in? Sentence22: Yes please, 6 people for 5 nights and we would be arriving Monday. Question: Who has spoken the sentence 21? (A) User (B) System
[EX A]: Answer: (B) System

[EX Q]: Sentence1: Will an arrival time of 22:01 work for you? Sentence2: It costs 17.90 pounds. I need to know your arrival time to determine the trainid. Sentence3: Have a nice day. Sentence4: Yes, I'll be leaving from cambridge. What's the train number and cost? Oh, and how long is the trip? Sentence5: will you be leaving cambridge? Sentence6: Where will you be traveling to? Sentence7: Yes, that would be fine. I'll need the price and travel time for that, please. Sentence8: I was able to reserve a table at Prezzo on Thursday at 16:00. The table will be reserved for 15 minutes, reference number R0Q4HL63 . Can I assist with anything else? Sentence9: No thank you that will be all Sentence10: I also would like to book a table for 3 at prezzo for 16:00 the same day I arrive or Tuesday. I need the reference number also. Sentence11: I have 2 trains going to broxbourne, do you have an arrival time preference? Sentence12: I'm looking for a train that leaves on Thursday after 21:30. Sentence13: I will be going to Broxbourne. Sentence14: i just want to leave after 21:30 Question: Who has spoken the sentence 4? (A) User (B) System
[EX A]:
Answer: (A) User