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

Sentence1: Sorry, that doesn't really narrow it down, they all have plenty of open seats. Sentence2: It is free to get in. The postcode is cb12lj. Can I help you with anything else? Sentence3: Train TR3922 is leaving at 19:19 and arriving at 20:09. Booking was successful for 3 tickets, totaling 39.59 GBP. The Reference number is : WF0T26CV . Sentence4: Ok, there are 10 different trains, what time did you want to arrive by so we can narrow it down a bit. Sentence5: Hi, I am searching for a museum to attend in the centre of town. Sentence6: You are welcome, goodbye! Sentence7: There are 11 total museums in the centre of town. Would you prefer suggestions for art museums, history museums, science museums, galleries...? Sentence8: Yes I would like a good steak. Sentence9: That sounds good. What is the entrance fee if any, and it's postcode? Sentence10: I don't care of the type of museum. Sentence11: No thanks, I actually need a train. I'll be heading to cambridge from peterborough on Sunday. I need to leave after 19:15. Sentence12: I can help you find a fantastic steakhouse. Do you have a preference for the area of price range of the restaurant? Sentence13: I would like to book the train with the shortest travel time, if that narrows it down. I will also need the reference number. Sentence14: I have located Williams Art and Antiques located at Gwydir Street, no. 5 Dale's Brewery. Would you like to visit this museum or would you like another suggestion? Sentence15: Thank you very much. That was all I needed. Have a great day. Sentence16: Before that, I need a booking for 3 people. Does that narrow it down? Question: Who has spoken the sentence 6? (A) User (B) System
Answer: (A) User