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: I'm happy to be of service, and enjoy your time in Cambridge! Sentence2: consider clare hall, which is a college in the western area of town Sentence3: Can you book a hotel room for me? Sentence4: Thank you so much for your help. Sentence5: That's all for today. Thank you Sentence6: The entrance fee is 2.50 pounds. Sentence7: Yes, how many people will be attending? Sentence8: Best choice will be the Cambridge Belfry, rated at 4 stars, but very inexpensive. What night will you be checking in, so I can get a booking started for you? Sentence9: I'd like cheap. Sentence10: You are quite welcome. Can I be of any further assistance for you today? Sentence11: Please book it for 5 people and 5 nights starting from monday. Sentence12: I'd love to. What price range where you looking in? Sentence13: pick a free one for me and get me the entrance fee Sentence14: What is the entrance fee? Sentence15: There are 5 in that area. 3 have free entrance while the other 2 charge 2.50 pounds. Sentence16: Yes, i am looking for a college to visit on the west side of town.. Sentence17: Your reservations have been made. Your reference number is X1ZCL9AO . Is there anything else I can assist you with? Sentence18: Yes can you please book that for me? Question: Who has spoken the sentence 4? (A) User (B) System
A:
Answer: (A) User