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: Of course! Your reference number is J4Y78RXR . May I help with anything else? Sentence2: I am leaving from Cambridge and going to Birmingham New Street. I would also like to leave after 21:00. Sentence3: I have 13 colleges. I like the emmanuel college but is there another one you had in mind? Sentence4: I would like to see a college in the centre area of town. Sentence5: Of course! So that I can better help you, can you give me the departure and destination cities you are considering? Sentence6: I have TR1012, leaving at 21:01 and arriving at 23:44. Will that work for you? Sentence7: Nope. Thank you for your help! Sentence8: Emmanuel college is on saint andrew's street. It is free admission. Can I help you with anything else today? Sentence9: It sure will if you can book 8 tickets for me. Sentence10: Yes please, can you help me with train schedules too? I need to travel on Sunday. Sentence11: Okay, have a great day! Sentence12: Can I get the reference number for the train please? Sentence13: Emmanuel college is fine. What's the address? Sentence14: Your booking was successful and your fee is 480.64 GBP. Can I help you with anything else today? Question: Who has spoken the sentence 5? (A) User (B) System
Output:
Answer: (B) System