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

Example input: Sentence1:i need a place to dine in the center thats expensive Sentence2: I have several options for you; do you prefer African, Asian, or British food? Sentence3: Any sort of food would be fine, as long as it is a bit expensive. Could I get the phone number for your recommendation?Question: Who has spoken the sentence 2? (A) User (B) System
Example output: Answer: (A) User
Example explanation: The sentence 1 is said by a user because the intent of it says that the information has to be gathered from the system
Q: Sentence1: Yes please book the restaurant for me. Sentence2: Booking was unsuccessful. Would you like to book another day or a shorter day? Sentence3: I have successfully booked you a taxi! You will be driven in a Black Toyota and the contact number is 07914565807. Can I help you with anything else? Sentence4: There are a few hotels that meet your criteria. Would you be interested in the Alexander Bed and Breakfast? It has four stars with cheap prices. Sentence5: The booking was successful at the University Arms Hotel. Your reference number is: E7AK16IK . Would you like the phone number? Sentence6: There are 2 hotels in the expensive price range. One has 3 stars and one has 4 stars. Sentence7: No, that's all I need. Thank you for your help! Sentence8: I also need a restaurant the restaurant should be in the expensive price range and serve north american food. Sentence9: The hotel should be in the expensive price range. Sentence10: Please try to book a 1 night stay. Sentence11: I changed my mind. I will go ahead and book it myself. But, can you please provide me the address and postcode. Thanks. Sentence12: Could you book me a taxi please? I would like to leave the restuarant at 20:15 and go back to the hotel. Sentence13: The only result in your area meeting that criteria is Gourmet Burger Kitchen in centre. Would you like me to book a table for you? Sentence14: No problem. You have a good day now! Sentence15: Hello, are there any centrally located hotels in Cambridge with free parking? Sentence16: Gourmet Burger Kitchen is located at Regent Street City Centre, cb21ab. Can I help with anything else today? Sentence17: Not a problem. For what time and day will that be for? Sentence18: Let's go with the 4 star option. I'd like to book it for two people and three nights starting from thursday. Question: Who has spoken the sentence 15? (A) User (B) System
A:
Answer: (B) System