You will be given a definition of a task first, then some input of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: You're all set! Your reference number is XDENSO4L . Do you need anything else? Sentence2: Thanks for the help, that's all for now. Sentence3: We're willing to experiment. I have 7 people. Anything you recommend? Sentence4: Okay, let's go with that one. I need a table for 7 at 19:15 on Saturday. Sentence5: There are 21 matches. What type of food do you want? Sentence6: Sure, we have a lot of trains. Where are you heading to? Sentence7: Yes, please book that for 7 people. Sentence8: There don't seem to be any trains going to Ely from Peterborough. Sentence9: I need suggestions for a moderately priced restaurant in the center part of town. Can you help me? Sentence10: I will be heading to Ely. Sentence11: You're welcome, glad I could help. Sentence12: There is a British restaurant named cotto that you may want to try. Sentence13: Yes, very serious. I'm not sure why but it appears all of those trains have been cancelled. Sentence14: Your total is 92.4 GBP, which you can pay at the station when you pick up the tickets. Your Reference number is : DWZ3T4RK . Sentence15: Wait, what? Are you serious? Sentence16: I think we got some crossed wires. I need the train from peterborough to cambridge. I need it for Saturday. Sentence17: Yes, if you could also help me find a train that will depart from Peterborough. Sentence18: Yes, I just need to arrive by 12:15. Sentence19: There are 13 trains that would get you to Cambridge by 12:15. Train TR8494 would arrive at 12:09. Would you like me to book a seat for you? Sentence20: Okay, please book the train for 7 people on Saturday. Sentence21: Do you have a specific departure time or arrival time in mind before I book the train? Sentence22: there is a train that leaves at 05:19 am. Question: Who has spoken the sentence 6? (A) User (B) System
Output:
Answer: (A) User