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

Sentence1: I am planning a trip in Cambridge Sentence2: Are there any expensive restaurants in the south? Sentence3: What time and where are you departing and arriving? Sentence4: Yea, please book me for 8 people on wednesday at 14:30. Sentence5: I'll be leaving Cambridge going to Ely, I'd like to leave after 10:00. Sentence6: Nope you've been wonderful, thanks for all the help. Sentence7: I also need a train. Sentence8: Frankie and bennys is available, would you like to book it? Sentence9: There is one that leaves at 11:50 arriving at 12:07. Would that work for you? Sentence10: There are five expensive restaurants in the south. Would you like Mexican, Italian, Indian, or Chinese food? Sentence11: You are all set, the reference number is OY6PZ53J cost is 35.2 GBP payable at the station . Any other questions today? Sentence12: Booking was successful. The table will be reserved for 15 minutes.Reference number is : 1E5RVHJE .is there any other way i can help you? Sentence13: great, what would you like to know? Sentence14: Unfortunately, I am unable to book at this time. Sentence15: I would like it to leave after 10:00. Sentence16: Thank you for the call, have a great trip. Sentence17: It does and could you please book it for 15 people and could you also give me the reference number? Sentence18: There are 2058 trains to pick from. I'll need to know your departure and destination locations Sentence19: Sorry I actually need that for 8 people on Thursday. Sentence20: italian food willl do Question: Who has spoken the sentence 6? (A) User (B) System
Answer: (A) User