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

Sentence1: Yes, see if 15:00 is available. Sentence2: I am sorry, I was unable to reserve a table for that time on Saturday, would you like to try a different time slot? Sentence3: I need a guesthouse in the cheap price range. Sentence4: Yes, I am also looking for a restaurant called The Nirala. Sentence5: Do any of these hotels have 4 stars? Sentence6: Booking was a success! Sentence7: Any area is fine, but I'd like to book rooms for 8 people. We'll be staying 5 nights, beginning on Saturday. Can any of them accommodate that? Sentence8: I have many results for a cheap guesthouse, would you like to narrow it down to stay in a particular area of the town? Sentence9: Glad that I could be of service. Goodbye! Sentence10: I'd like to book a table there for 8 at 16:00 on Saturday, please. Sentence11: I was able to get you rooms at the Alexander Bed & Breakfast. Reference number is : HREOM15W . Can I be of further assistance today? Sentence12: The nirala serves indian food in the north side of town. It is located at 7 Milton Road Chesterton, phone 01223360966. Is there anything else I can help with? Sentence13: Could you please provide the reference number? Sentence14: Great - that's all I need today. Thanks for your help! Sentence15: Sure thing. The reference number is Z1YHIR0Y . Sentence16: Yes, in fact 7 of the 9 hotels in your search criteria have 4 stars. Would you like to narrow your search by area? Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User

Sentence1: Great. You should expect a blue volkswagen . You can contact them on 07261965496 Sentence2: Where will you be headed? Sentence3: Thank you! That's all I need for now. Sentence4: Great, I hope you have a great visit! Sentence5: I'll be headed to the Cherry Hinton, of course. Sentence6: THanks so much you have been a huge help. Sentence7: Can you help me find a moderately priced restaurant in the center of town? Sentence8: How about asian oriental that is in the moderate price range located in the centre of town? Sentence9: cool I would need the address, postcode, and phone number. Sentence10: There is no information on the entrance fee since there are a variety of facilities. Anything else I can help with? Sentence11: How about the cherry hinton village centre? Sentence12: Sure, I can help with that. Is there a certain cuisine you are looking for? Sentence13: That sounds perfect! Do you know the entrance fee? Sentence14: Have a nice day. Good bye. Sentence15: Okay, great. I'm also looking for an attraction in the same area. I'd like it to be multiple sports. Sentence16: No preference really. whatever you recommend Sentence17: Okay, the yippee noodle bar is at 40428 King Street City Centre postal code cb11lh and it's number is 01223518111. Is there anything else I can help you with? Sentence18: I need to book a taxi to commute between the 2 places. I want to leave the restaurant by 14:30. Question: Who has spoken the sentence 15? (A) User (B) System
Answer: (B) System

Sentence1: That is all I need, thank you! Sentence2: Where will you leave from? Sentence3: I'm leaving from birmingham new street train station. Sentence4: Booking completed! Booked car type : red lexus Contact number : 07427709999 Sentence5: I need a 04:00 taxi at the Cambridge Lodge Restaurant. Sentence6: You're quite welcome. Thanks so much for using the Cambridge TownInfo Centre. Have a great day! Goodbye. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User