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: Booked! fee is 56.32 GBP payable at the station. Reference number: G5DHGHZV . Also do you have an area preference for the hotel? Sentence2: Sure how many tickets? First train leaves at 05:16 and the last 09:16. Do you have specific time in mind? Sentence3: That should work, can I please get a reference number? Also, I am looking for a place to stay in the moderate price range that is 4 stars. Sentence4: No, but I would prefer a guest house. Sentence5: Just any moderate guest house with 4 stars that you recommend. I need it for 3 nights for my group. For the same day we are traveling. Sentence6: We have 33 total entries that match you criteria, location varying from north, south, and east. Would you like any more information on them? Sentence7: The train should depart from norwich and should arrive by 17:15. for 4 people Sentence8: I've booked your group rooms at the Acorn Guesthouse for Saturday, staying 3 nights. Reference number is 8Y6XQ1PM . Need anything else today? Sentence9: Thank you for using our service. Have a great day. Sentence10: I'd like a train leaving from Norwich and arriving by 17:15, please. Sentence11: I'll be going to Cambridge on Saturday. Sentence12: No that was all thank you. Sentence13: How about TR1156, it will depart Norwich at 15:16 and will arrive in Cambridge at 16:35? Does this work for your schedule? Sentence14: Certainly! First, can you confirm the day you are traveling and the destination you are traveling to? Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User