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 today! Sentence2: I am coming to cambridge and heard about a bed and breakfast called finches. Sentence3: Yes, I would like to arrive before 5:00 PM. Sentence4: It is a lovely guesthouse on the west end boasting cheap prices and a 4 star rating! Would you like their address or phone number perhaps? Sentence5: I actually would like to book the hotel for 7 people starting on Tuesday for 3 nights. Sentence6: I'll be departing from cambridge and going to norwich. Sentence7: I apologize, I actually need to leave after 16:30 Sentence8: No problem, but I'm afraid there are no trains leaving after 16:30 and arriving by 17:00. Might I suggest TR7047, which leaves Cambridge at 16:36 and arrives in Norwich by 17:55? Sentence9: Is there a time you would like to arrive before? Sentence10: Can you also help me find a train on Fridya? Sentence11: Train TR7747 leaves at 15:36 and arrives in Norwich at 16:55. Would you like me to book you tickets? Sentence12: Thank you, no that will be all. Sentence13: OK, the booking for successful. The total is 17.6 GBP and the reference number is MIMOPEN1 . Is there anything else I can do for you? Sentence14: Yes, that sounds great. Please book that for me. Sentence15: I was able to book your party of 7 at Finches bed and breakfast for 3 nights. Your reference number is 4R76GWVJ . Can I help you with anything more today? Sentence16: Of course. There are many available Friday. Where will you be traveling to and from? Question: Who has spoken the sentence 7? (A) User (B) System
Output:
Answer: (B) System