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

[EX Q]: Sentence1: It does not matter, I just need one available for 7 people at 18:15 on thursday Sentence2: I'm sorry, nothing is coming up for that particular type of restaurant. Is there any other specifics you may like? Sentence3: The reference number is DVDLH9NK . Is there anything else I can help you with? Sentence4: Unfortunately I could not find any guesthouses meeting those requirements. Sentence5: How many stars is Cityroomz? Sentence6: Before I can book your taxi, what time are you wanting to leave or arrive by? Sentence7: Fantastic. Enjoy your trip! Sentence8: Not yet. I would like you to book a taxi for me between my hotel and restaurant. I will need the car type and contact number. Sentence9: It has a zero star rating, is this ok? Sentence10: I also need the reference number please. Sentence11: I just want to be sure it arrives by the booked time at the restaurant. Sentence12: Cityroomz is the only place that matches your criteria. Sentence13: That is fine. Do they have internet? Sentence14: I have made a reservation at restaurant alimentum for you. Your table will be reserved for 15 minutes. The address is 152 - 154 Hills Road. Sentence15: How about one that serves modern european food? Sentence16: Thank you very much for your help! That was everything I needed. Sentence17: How about a hotel type? Sentence18: There are 3 restaurants serving modern european food, would you prefer one on the south side or town centre? Sentence19: Yes, Cityroomz has internet. Would you like to book it? Sentence20: Booked. Your car type is white skoda and contact number is 07075801794 Sentence21: Can you find me restaurant with moderate prices that serves north indian cuisine? Sentence22: Yes, I also need a guesthouse hotel with moderate prices in the centre. I don't need free parking. Question: Who has spoken the sentence 15? (A) User (B) System
[EX A]: Answer: (B) System

[EX Q]: Sentence1: The phone number for pizza hut cherry hinton is 01223 323737 and they are located at G4 Cambridge Leisure Park Clifton Way Cherry Hinton. Sentence2: There are two restaurants: Pizza Hut Cherry Hinton and Restaurant Alimentum. Sentence3: No, there are only 2 restaurants in the area. Is there anything else I can help with? Sentence4: Give me the address and postcode of any of them, please. Sentence5: That's great. Thank you so much Sentence6: What kind of food do you want? italian or modern european? Sentence7: The postcode is C.B. 1 7 D.Y Sentence8: Is there anything else available? Sentence9: Hello, I am looking for a moderately priced restaurant in the south part of town. Sentence10: I do not care. Sentence11: What is the postcode? Sentence12: You're very welcome. Question: Who has spoken the sentence 6? (A) User (B) System
[EX A]: Answer: (A) User

[EX Q]: Sentence1: There are 5 entries for Italian food in the cheap price range. Is there an Area of town that works best for you North, Centre, or West? Sentence2: I would like a cheap restaurant that serves greek food Sentence3: How about Da Vinci Pizzeria? It is located at 20 Milton Road Chesterton and the phone number is 01223 351707. Sentence4: It doesn't matter. Sentence5: Please check for Italian food. I will also need the address and phone number. Sentence6: Thank you. Goodbye! Sentence7: I cannot locate a cheap Greek restaurant. Is there another one that you are interested in. Sentence8: Thank you for using our service, good bye. Question: Who has spoken the sentence 7? (A) User (B) System
[EX A]:
Answer: (B) System