Detailed Instructions: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: Looking for something in the North, cheap price range please. Don't care much about internet. Sentence2: Your booking was successful. Your reference number is G7TDBIJU . Sentence3: Thank you that will be all I need. Sentence4: Can you book the worth house for 5 nights starting saturday for 7 people. Sentence5: I need a train to stansted airport from cambridge please. Sentence6: Okay, have a nice day! Bye! Sentence7: Ok, what day will you be traveling? Sentence8: There are two guesthouses that meet your criteria. The City Centre North B and B, and the Worth House. Would you like me to book one of those for you? Sentence9: What part of town would you prefer? And, do you need internet? Sentence10: I have booked the Worth House for you. The reference number is G7TDBIJU . Is there anything else I can help you with? Sentence11: I need to find me a room as well. Sentence12: The closest to thing I can find is a train leaving at 5:40 on Thursday. It arrives at Stansted Airport at 6:08. Is this okay? Sentence13: Does the Worth House have a star rating of 4? Sentence14: Yes, that works. Can I get the train id number and the price please? Sentence15: Sure, Saturday for 5 nights and 7 people. Sentence16: Thursday. I need to arrive by 12:45. Sentence17: the train Number is TR7966, it will cost you 10.10 pounds. Sentence18: Yes, the Worth House has a 4 star rating. Is there anything else I can help you with? Question: Who has spoken the sentence 13? (A) User (B) System
A:
Answer: (B) System