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: Thank you for using our system! Sentence2: I'll be leaving from Cambridge. Sentence3: Were you able to book it for 4 people? Sentence4: Okay no that is all today. Sentence5: Booking was successful, the total fee is 8.08 GBP payable at the station. Reference number is : V6E0H0GJ . Is there anything else I can help with? Sentence6: Certainly. Where are you departing from? Sentence7: The arrival time does not matter, but it should leave on Sunday after 15:15. Sentence8: I was able to book 4 tickets. The total fee will be 32.32 pounds, payable at the station. The reference number is BPUJ9ISP . Can I help you with anything else? Sentence9: I have several trains, when would you like to arrive by? Sentence10: I am looking to leave for bishops stortford after 15:15 by train. Question: Who has spoken the sentence 6? (A) User (B) System
Output:
Answer: (A) User