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

Sentence1: I think you'd like TR8842 train, it costs 23.60 pounds. Sentence2: Thanks, it would be helpful if you also told me what time TR8842 leaves. Anyhow, I just got paid. Can you find me a high-end eatery serving European cuisine? Sentence3: No thank you. I'll just need the address for an expensive restaurant that serves European food. Sentence4: Train TR8842 leaves london kings cross at 15:17 on friday and arrives at cambridge at 16:08. Can I provide you more information or book it for you? Sentence5: Arrival time is not important. I just need to leave after 14:15. I will need the train ID and the price, please. Sentence6: Sorry! As I said, it's at Free School Lane City Centre. Can I help you with anything else? Sentence7: Hi, could you help me find a train going to Cambridge? Sentence8: Is there a time you would like to arrive by? Sentence9: Where and when are you departing from? Sentence10: I would like to leave on Friday Sentence11: No, that's it. Thank you. Sentence12: which side of town is most appropriate for you? Sentence13: Have a lovely day, goodbye. Sentence14: I am leaving from London Kings Cross after 14:15. Sentence15: I'm sorry, but I think you gave me the phone number. I need the address, please. Sentence16: I don't have a preference really, please recommend one. Sentence17: no. i just need the address Sentence18: What day would you like to leave? Sentence19: its address is 01223368786. is that it? Sentence20: How about the eraina located at Free School Lane City Centre. Would you like reservations? Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User

Sentence1: You're very welcome. Thank you and goodbye! Sentence2: The earliest train departs Leicester at 05:09 and arrives in Cambridge at 06:54. The cost is 37.80 pounds per ticket. Sentence3: That's all that I need. Sentence4: Any of those will work. Which one is your favorite and where is it located? Sentence5: I'll be departing from Leicester, headed to Cambridge. What do the prices look like? Sentence6: No problem. There are a lot of other options like boating, cinema, colleges, a concerthall, museums, nightclubs, a park, theatres and swimming pools. What are your interests? Sentence7: I also need a train on Wednesday, arriving by 19:00. Sentence8: I'm looking for something to do in the centre of town. Sentence9: Travel time is approximately 105 minutes. Sentence10: Would you like any more information on other attractions? Sentence11: I would really like it to be a attraction type. Sentence12: What is the travel time? Sentence13: Great! I found a lot of things that match what you're looking for. Do you like architecture? Sentence14: I can help you with that. What are the departure and destination cities you were looking for? Sentence15: No, that will be all. Thank You for all your help. Sentence16: I'd try the cambridge contemporary art museum, at 6 trinity street. Question: Who has spoken the sentence 13? (A) User (B) System
Answer: (B) System

Sentence1: The price per ticket on TR8932 is 9.8 GBP. Will that be all? Sentence2: Does it have free parking and internet? Also, I'd like to be in the centre of town. Sentence3: I don't care but it needs to be cheap. Sentence4: Wonderful, could I just have the price for now? I may book myself later. Sentence5: Okay, the allenbell is a cheap guesthouse, would you like me to make a booking? Sentence6: I have the Alexander Bed and Breakfast guesthouse available in the centre. It's cheap, 4 stars, with free wifi and parking. It's in postcode cb12de. Would that work for you? Sentence7: Hi, I'm looking for a guesthouse in Cambridge. Sentence8: We have 11 trains matching your request. Was there a specific time you wanted to depart? Sentence9: What is your departure and destination locations? Sentence10: Yes thank you. I also needs a train on tuesday that arrives by 16:15. Sentence11: I would like to depart from kings lynn and go to cambridge. Sentence12: I have found 24 guesthouses in cambridge. Is there a particular area you are wanting to stay in? Sentence13: Yes, thank you so much! Goodbye! Sentence14: TR8932 will arrive at 15:58 would that work for you? Sentence15: Yes it does and it in the east though, is that going to be problem? Sentence16: Yes, I need one that is in the centre. Please give me the postcode, price range and star of the hotel. Sentence17: Whichever one gets me to Cambridge closest to 16:15. Sentence18: Thank you for using our system! Question: Who has spoken the sentence 6? (A) User (B) System

Answer: (A) User