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

[EX Q]: Sentence1: Maybe you could try again? Sentence2: I am looking for a place to stay in cambridge in the moderate price range with 4 stars Sentence3: I found the restaurant you want. Do you want me to make reservation? Sentence4: I am having a hard time booking this, could I make sure the place you would like is the Pizza Express at Fen Ditton? Sentence5: There are 11 matches. Do you have a preference for hotel types? Sentence6: Yes, for 5 people on Friday around 13:45, please Sentence7: I am not able to book anything right now. Sentence8: Okay....well I'm over here waiting....don't forget the reference number too Sentence9: I will go ahead and book that for you now. Sentence10: Thanks for the room booking. Can you locate a restaurant for me, too? The name is pizza express Fen Ditton. Sentence11: The booking worked this time! The reference number is S31A87TV . Anything else today? Sentence12: No problem. If you need anything else just call us back. Sentence13: Yes it is, but if 13:45 time isn't working then 12:45 would also be acceptable. Sentence14: Great, thanks for your help! Have a good one. Sentence15: You have a room booked at the Warkworth House (ref# TP8X26LA). Can I help you with anything else? Sentence16: No, but it should be in the east. Sentence17: I have 3 guesthouses matching your request. Do you care about parking? Sentence18: Pick one and book me for 5 people lasting three nights starting Friday please. Question: Who has spoken the sentence 15? (A) User (B) System
[EX A]: Answer: (B) System

[EX Q]: Sentence1: I'll be leaving from Leicester and want to go to Cambridge. Sentence2: Booking was successful, reference number is YN5MH1ZN . Anything else I can help you with? Sentence3: Where are you departing from and what is your destination? Sentence4: I need a hotel in the north that has free parking. Sentence5: There are 11 different hotels. To help narrow it down, can you tell me if there is a price range you prefer? Sentence6: All right. I need a booking for six, please, and the reference number. Sentence7: Yes it is. Sentence8: There are 91 trains leaving Leicaster to Cambridge after the specified time. How does Friday 11:09 sound? Sentence9: No thank you that will be all. Thank you for your help in booking my trip and stay! Sentence10: How about the Acorn guest house on 154 Chesteron Road? It's a moderate price range guesthouse that is rated 4 stars with free parking and wifi. Sentence11: Perfect. I'd like to book a 5 night stay for the six of us. Sentence12: Great. Is this hotel stay also starting on Friday? Sentence13: No problem! You have a wonderful day! Sentence14: I'm looking for a train leaving after 10:30. Sentence15: No not really, I would prefer a guesthouse type of hotel with free wifi though. Sentence16: I was able to book the train for you for 6 people. The reference number is 7QAMUGHQ . Do you need anything else? Question: Who has spoken the sentence 15? (A) User (B) System
[EX A]: Answer: (B) System

[EX Q]: Sentence1: The postcode is cb30nd. Would you like to book a room now? Sentence2: What is the star rating and is free parking available? Sentence3: Yes can you please help with that? Sentence4: Can you give me the postcode? Sentence5: Absolutely. How many people, what day are you arriving, and how many nights will you be staying? Sentence6: enjoy your stay! Sentence7: It's 4 stars and has free parking. Would you like a room? Sentence8: The TR8600 Departs Norwich at 18:16, and it takes 79 minutes to get to Cambridge. The fare is 14.08 GBP per ticket. Is there anythig else you want to know? Sentence9: I need a place to stay in the west. Sentence10: Finches Bed and Breakfast is within your chosen price range and it is located at 144 thornton road. Sentence11: I would like to find a cheap guesthouse. Sentence12: How long is the travel time, departure time and what is the price? Sentence13: No actually I need to find a train to Cambridge from Norwich on Saturday arriving by 19:45. Sentence14: Okay the TR8600 arrives by 19:35. Would you like tickets? Sentence15: We have several places to stay that you may like in the West. Do you have a specific price range or star rating in mind? Sentence16: Nope, that's it. Thanks! Question: Who has spoken the sentence 4? (A) User (B) System
[EX A]:
Answer: (A) User