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

[Q]: Sentence1: Sorry. TR2052 departs from leicester and the destination is cambridge. It leaves at 15:09 on Wednesday. Would you like me to book it for you? Sentence2: Yes, I only need 1 ticket for myself. Sentence3: There are 13. I could recommend Trinity College on Trinity Street. Or would you like information about one of the others? Sentence4: I would like to arrive by 17:00 in leicester. Sentence5: I would like help finding a college to visit in the centre of town. Sentence6: Of course. The address is Trinity Street, postcode is CB21TQ, and the entrance fee is one pound. Can I help you with anything else? Sentence7: Yes and please give me the reference number. Sentence8: OK, I've booked one ticket for you on TR0451 from cambridge to leicester, arriving at 16:06. Ref# 8OZNJHMO . Can I help you with anything else today? Sentence9: That sounds good. Could you give me the entrance fee, phone number, and postcode? Sentence10: Certainly. Just to verify, are you traveling alone? You would only like one ticket? Sentence11: TR3702 LEAVES AT 05:00 CAN I BOOK THAT ONE FOR YOU? Sentence12: How early do you wish to arrive? There are 11 trains that will get you there before 17:00. Sentence13: Thank you for using our service. Have a good night. Goodbye. Sentence14: Does this train go to Leicester from Cambridge? Sentence15: Yes I'm also looking for a train that leaves wednesday and arrives by 17:00. Sentence16: I think that is all I need, thank you. Question: Who has spoken the sentence 4? (A) User (B) System
[A]: Answer: (A) User


[Q]: Sentence1: Ok great! I was able to get you booked, your reference number is N4TJE8VR . Is there anything else that I can help you with? Sentence2: Yes please. There are 5 of us total and we need 4 nights in a row. Thank you. Sentence3: May I get your departure and destination information please? Sentence4: Can you verify the cost for train TR6954 for me? Sentence5: There don't seem to be any 5-star lodgings in the city. Would you like to try searching for 4 stars instead? Sentence6: I am looking for a train arriving by 9:45 on Tuesday. Sentence7: I'd like to start my stay on Tuesday, please. Sentence8: Your booking reference is NT43PSC0 . Now, if you let me know what type of hotel you are interested in, I can help you with that as well. Sentence9: TR6954 departs from Leicester at 07:09 and arrives in Cambridge at 08:54. Would you like to book this train? Sentence10: What day would like to start your stay? Sentence11: Maybe... how much does it cost? Sentence12: Yes, 4 stars would be fine. Sentence13: Nope, that'll take care of everything, thanks! Sentence14: I am going from Cambridge to Leicester. Sentence15: I'm sorry, we have that mixed up. I need to depart from leicester and go to cambridge. Do you have a train that arrives by 09:45 in cambridge? Sentence16: The acorn guest house is a 4 star hotel located in the north side. Would you like to make reservations? Sentence17: You're welcome. Have a great stay! Sentence18: TR2863 departs from Cambridge at 07:21 and arrive in Leicester by 09:06. Would you like to book this train? Sentence19: Yes I would like help with booking the train and I will also need to book a hotel. Sentence20: It costs 37.80 pounds per ticket. Sentence21: The cost for this particular train is 37.80 pounds per ticket. Would you like assistance booking tickets for this train? Sentence22: Can you help me find a 5-star room somewhere that offers free parking and wifi? Question: Who has spoken the sentence 17? (A) User (B) System
[A]: Answer: (B) System


[Q]: Sentence1: You are welcome. Please call back if you need anything else. Sentence2: The phone number is 01223217300 and post code is CB20QQ. Sentence3: Do you need any further assistance? Sentence4: Great, thanks for your help. Sentence5: I want to find a hospital in town. The hospital should have the hepatobillary and gastrointestinal surgery regional referral centre department Sentence6: Addenbrookes Hospital is located at Hills Rd, Cambridge. They have the department you're looking for, would you like the phone number? Sentence7: That was all. Thanks Sentence8: I need the address, postcode, and phone number. Question: Who has spoken the sentence 1? (A) User (B) System
[A]:
Answer: (B) System