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: No thank you. Can I have to phone number and postcode for that restaurant? Sentence2: I need a train to Kings Lynn. Sentence3: Thank you for using our service. Sentence4: The earliest train leaving after 17:00 on Friday leaves at 17:11. Would you like me to book this train for you? Sentence5: That would be TR9226 Sentence6: The phone number is 01223247877. It's located in the cb13nl postcode. Sentence7: Hmmm....how about an expensive restaurant serving gastropub food in the east? Sentence8: Thank you, goodbye. Sentence9: I am looking for a restaurant in the east that serves international food. Sentence10: No. There are two moderately priced restaurants with international cuisine in the centre of town. Would you like to hear about those? Sentence11: Book it, please. I need a single ticket. Sentence12: The the missing sock fits that criteria and is in the cheap price range. How else can I assist you? Sentence13: What day would you be wanting to travel? Sentence14: There's one restaurant that fits your requests, would you like me to book a reservation? Sentence15: Thanks again for the information! Sentence16: Have a great time. Sentence17: Have a great day as well. I think you'll love the Royal Standard. Sentence18: Thank you so much. Have a nice day! Sentence19: Friday please. From Cambridge leaving after 17:00 Sentence20: Can you give me the train ID on that one please? Sentence21: Is there one in the expensive? Sentence22: You have been booked for the train. Your reference number is 0UIC4MX9 . Can I help you with anything else? Question: Who has spoken the sentence 20? (A) User (B) System
[EX A]: Answer: (A) User

[EX Q]: Sentence1: Yes please book it for one person for 2 nights starting friday. Sentence2: Sure. Your booking was successful and I have a reference number for you. It is IBDDDIAJ . Sentence3: Thank you for using our service today. Sentence4: I'm looking to get some info on a hotel called cityroomz. Sentence5: Thank you very much for your help. Have a great day. Sentence6: I've found it, would you like me to book it for you? Question: Who has spoken the sentence 3? (A) User (B) System
[EX A]:
Answer: (B) System