You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: There are 4 guesthouses that meet your criteria. The Hobsons House is popular. Would you like to book it? Sentence2: Yes, I also need a taxi. Sentence3: Where would you like to travel and what time would you like to go? Sentence4: Yes - I'm looking for a 3-star place to stay. Something moderately priced. Sentence5: You are booked at the Hamilton Lodge for three days starting Monday, and your confirmation number is 1ROQGKD4 . Can I assist you with anything else? Sentence6: The folk museum sounds interesting. Can I get the address and entrance fee? Sentence7: I am not showing an architecture in the west. Would you be interested in a different type of attraction or a different area? Sentence8: In the North and Moderately priced we have hamilton lodge and alpha-milton guest house. Sentence9: Thank you for the info on the taxi and helping me find one have a great day! Sentence10: Hi, I want to find an architecture attraction in the west please. Sentence11: Are there any museums in the west? Sentence12: Yes. There are 7 museums in the west. I can recommend the cambridge country folk museum and kettle's yard. Would either of those interest you? Sentence13: I wish you a lovely day too. Sentence14: Their address is 2-3 castle street and the fee is 3.50 pounds. Is there anything else that I can help you with? Sentence15: As long as it is in the North, and meets that criteria, sure. Sentence16: Hamilton lodge and book for 2 people for 3 nights starting monday, please. Sentence17: The contact number is 07050010887 and it will be a white Ford. Sentence18: I want to leave the folk museum by 2:30 to go to the hotel. Can you get me the contact number and car type? Question: Who has spoken the sentence 15? (A) User (B) System
Answer: (B) System