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

[EX Q]: Sentence1: There is a restaurant called Thanh Binh. Would you like me to book a table? Sentence2: Yes i would like a table for 7 people on monday at 13:15 Sentence3: We would prefer vietnamese please. In the west area? Sentence4: How many tickets would you like me to book? Sentence5: The travel time is 49 minutes. Would you like to know any more info? Sentence6: Thank you, what is the arrival time? Sentence7: Your reservation has been set for Monday at 12:15 for 7 people. The reference number is 3MTLQCBA . Can I do anything else for you? Sentence8: I am leaving from Cambridge and headed to Stevenage. I would like to leave after 17:30 please. Sentence9: Just one ticket, please. Sentence10: Certainly. The train will arrive at 20:10. Can I help you with anything else? Sentence11: Can you tell me when that train will be arriving in stevenage? Sentence12: Alright, TR6692 looks like your best bet. Would you like me to book you passage? Sentence13: Thank you I also need a train on tuesday leaving after 17:30 Sentence14: I think that about does it. Thanks for the help today. Sentence15: I need to find a cheap place to eat. Sentence16: Booking was unsuccessful do you have any other preference? Sentence17: Can you try 12:15 on Monday? Sentence18: I've booked that ticket for you. The reference number is FTLHURXQ, and the total fee is 12.8 GBP. Sentence19: It was my pleasure to assist you. Thanks for using our service. Have a wonderful day. Goodbye. Sentence20: Yes. Please book that for me. Thanks so much! Sentence21: I can find that for you. What cuisine are you interested in? Sentence22: I would be happy to help with that. Can you tell me the departure city and where you are going? Question: Who has spoken the sentence 11? (A) User (B) System
[EX A]: Answer: (B) System

[EX Q]: Sentence1: You're welcome, enjoy your day. Sentence2: How about Downing College? It has free admission and is located on Regent Street/ Sentence3: I'd like to visit a college in the center of town. Could you help me find something interesting? Sentence4: That sounds great! Can I have their phone number and postcode, please? Sentence5: No, that was all I needed to know. Thank you, you've been very helpful. Sentence6: Downing College's phone is 01223334860 and their postcode is cb21dq. Can I help you with anything else today? Question: Who has spoken the sentence 4? (A) User (B) System
[EX A]: Answer: (A) User

[EX Q]: Sentence1: Thank you, goodbye Sentence2: Hi, I'm looking for a train that is going to cambridge and arriving there by 20:45, is there anything like that? Sentence3: That sounds great, could you make a booking for me please? Sentence4: Can you confirm your desired travel day? Sentence5: Thanks so much. I would also need a place to say. I am looking for something with 4 stars and has free wifi. Sentence6: That will, yes. Please make a booking for 5 people please. Sentence7: Please book it for Wednesday for 5 people and 5 nights, please. Sentence8: How about the cambridge belfry? It has all the attributes you requested and a great name! Maybe even a real belfry? Sentence9: I would like to leave on wednesday Sentence10: Goodbye. If you think of anything else you need don't hesitate to contact us. Sentence11: What day would you like your booking for? Sentence12: There are over 1,000 trains like that. Where will you be departing from? Sentence13: I've booked your train tickets, and your reference number is A9NHSO9Y . Sentence14: I show a train leaving birmingham new street at 17:40 and arriving at 20:23 on Wednesday. Will this work for you? Sentence15: Booking was successful. Reference number is : 5NAWGJDC . Sentence16: I am departing from birmingham new street. Question: Who has spoken the sentence 12? (A) User (B) System
[EX A]:
Answer: (A) User