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

Sentence1: Booking was successful for Tuesday. Your Reference number is : 0J3V1091 . Sentence2: I'm sorry that doesn't seem to be available would you like me to try a different day or guesthouse? Sentence3: I'm sorry, there does not seem to be a historical site or hiking area in Cambridge. Is there anything else I can help with? Sentence4: Sure, I can help you with that. What section of town were you looking for? Sentence5: Doesn't really matter if they offer either of those or not. I just want it to be a 0 star hotel. Sentence6: Then the city centre north b and b is what you want, shall I book you? Sentence7: i don't really care about the area. Sentence8: I want to see local sights, can you help? Sentence9: I like hiking and seeing historical sites. Sentence10: Okay. Are you interested in hotels that offer internet and/or parking? Sentence11: Yes, I would like to find a hotel in the cheap price range? Sentence12: Yes, a guesthouse is fine. I was looking for zero stars and in the cheap price range. Sentence13: Great, thanks. I don't need anymore help. Goodbye! Sentence14: Yes, please book it for me. Sentence15: I'm sorry, I seem to be having an error in my system. You want a booking at the citycentre north B&B for 6 people, 5 nights, on Monday? Sentence16: I'm also looking for somewhere to go. Perhaps the college. Can you tell me the postcode for the college? Sentence17: City Cenrtree North and B is a cheap hotel,would you like me to book it for you ? Sentence18: Let book the same but on Tuesday instead. Sentence19: I'm happy I could help today. Goodbye! Sentence20: There are 18 colleges in town. I recommend christ's college in the centre. The postcode is cb23bu. Sentence21: Yes, there is a wide variety, do you have an activity type that your are interested in? Sentence22: Yes please, 6 people for 5 nights and we would be arriving Monday. Question: Who has spoken the sentence 21? (A) User (B) System
Answer: (B) System

Sentence1: Kymmoy is in the centre of town and the phone number is 01223 311911. May I help you with anything else? Sentence2: Thank you, I have all I need. Goodbye! Sentence3: What is the phone number and area? Sentence4: Is there any expensive restaurants in town serving Australian food? Sentence5: You're welcome. Thanks for your call! Goodbye. Sentence6: Kymmoy is an expensive asian oriental restraunt in town. Sentence7: I'm sorry, there are no Australian restaurants. Would you like another type of food? Sentence8: How about asian oriental food? Question: Who has spoken the sentence 2? (A) User (B) System
Answer: (A) User

Sentence1: You're welcome. Enjoy your visit. Sentence2: I am looking for an expensive hotel. Sentence3: I'm sorry our system doesn't offer that choice, would you like the phone number? Sentence4: I have found The Oak Bistro. It is located at 6 Lensfield Road. Sentence5: No that was it. Thank you so much. Sentence6: Ok, all booked, your reference number is M6OWA41B . Sentence7: I found 5 moderately priced British restaurants. Would you prefer the center or west part of town? Sentence8: Cityroomz is the only hotel that fits that description, would this work for you? Sentence9: Yes, that works. I'd like to book for 4 people for 5 nights, starting on Saturday, please. Sentence10: The restaurant should be in the centre. Sentence11: I am actually looking for a moderately priced hotel and I will need free wifi. Sentence12: Sounds good. Can you book it for 4 people at 14:30 on saturday? I'll need the reference number. Sentence13: No that's okay but I am looking for a hotel in the same area as the restaurant can you please help? Sentence14: The contact number is 07171167823 and it is a yellow ford. Is there anything else I can help you with today? Sentence15: I am looking for a moderately price British restaurant. Sentence16: One last thing. May I have their contact number and car type please? Sentence17: There are five hotels in the center of town that range from cheap to expensive. What kind of place are you looking for? Sentence18: Can you hold the reservation for 30 minutes instead? Sentence19: Thank you. I will also need a taxi to to from the hotel to the restaurant. Sentence20: I have booked the table for you; it will be reserved for 15 minutes. The reference number is WAU3QQKF . Sentence21: There are two expensive hotels in the centre of town. The Gonville and University Arms. Which would you prefer? Sentence22: Ok, I've booked you a taxi from your hotel to your restaurant. It will get you there before your reservation time. Question: Who has spoken the sentence 19? (A) User (B) System
Answer: (B) System