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: Actually, I would like to book the Acorn Guest House for wednesday. Sentence2: Certainly! How many people are staying and how many nights will you require? Sentence3: The Castle Galleries are in the centre. Sentence4: What museums do you have in the centre? Sentence5: That sounds good. Can you tell me what the entrance fee is? Sentence6: Okay. Is there anything else I can do for you today? Sentence7: Great! Have a wonderful day! Sentence8: The booking has been completed. Your reference number is : 01P47PJ5 . Is there anything else I could do for you? Sentence9: Not at this time. Let me think about it. Thanks! Sentence10: Thanks. Can I also have the address and postcode? Sentence11: The entrance fee is free. Sentence12: Unfortunately, they were not available for that stay. Would you like to try a shorter stay? Sentence13: I found 5 guesthouses in the north. The Acorn Guest House has free internet and parking. Can I book this guesthouse? Sentence14: I need a 4 star place to stay in the north. Sentence15: Can we please try for 2 nights? Sentence16: No, you've been a great help. Thank you for your time. Goodbye. Sentence17: It will be 3 nights for 8 people. Sentence18: Certainly. The address is unit su43, grande arcade, saint andrews street and the postcode is cb23bj. Is there anything else I can help you with? Question: Who has spoken the sentence 17? (A) User (B) System
Output:
Answer: (B) System