Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: Okay. I have booked you for 2 at 12:00 at the Dojo noodle Bar on Sunday. Sentence2: 12:00 please, I will need a reference number. I also need a train that goes to stansted airport leaving after 10:30. Sentence3: Great thanks so much. Can you give me the reference number and also I need to get a train when your ready. Sentence4: Booking was successful for TR8207, the total fee is 20.2 GBP payable at the station. Your reference number is W7D3D21R . Is there any further assistance needed? Sentence5: Yes that is perfect, please also provide me with the reference number. Sentence6: I am looking for a cheaply priced restaurant in the centre of Cambridge. Sentence7: That should be all thank you Sentence8: No I'm not picky, anything is fine as long as it's in the centre of town. I need to make a reservation for 2 on Sunday. Sentence9: I need the train to leave Cambridge on Monday after 10:30 and go to Stansted Airport, and I need two tickets. I also need my reference number please. Sentence10: The reference number is RLOFK7YF . What do you need for your train? Sentence11: Have a great trip! Sentence12: What time would you like your reservation? Sentence13: There are a large number of options to choose from. Do you have a preference for the type of food you would like? Sentence14: There are 14 trains leaving Monday from cambridge to stansted airport after 10:30. The closest departure to that would be TR8207 leaving at 10:40. Shall I book this for 2? Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User