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: On what day will you be checking in, for how long, and for how many people? Sentence2: I have one leaving at 22:19. Would you like to book it? Sentence3: I don't feel comfortable giving that to you. I'll book on my own. Can you just give me info on a place to stay? Sentence4: The train ID is TR8054. May i have your details (Name, Phone number, ID, email) so i can go ahead and make the booking for you. Sentence5: The first train leaves at 21:48. Sentence6: Yes and Can you book it for me and get a reference number ? Sentence7: Okay, I have the alpha-milton guest house in the north area. Will that work for you? Sentence8: I am planning my trip to Cambridge and need a train leaving Peterborough after 21:45. Sentence9: Certainly. What area of town would you like to stay in? Sentence10: That won't work for me. When does the next one leave on Tuesday? Sentence11: I need a room. Do not need wifi or parking. Sentence12: Yes that time works. Please book it. What is the train ID? Question: Who has spoken the sentence 11? (A) User (B) System
Output:
Answer: (B) System