Q: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Sentence1: I need a train out of cambridge on Sunday, please. Sentence2: Yes there are 4 options to choose from, do you have a specific part of town you'd prefer? Sentence3: We have trains leaving every hour starting at 05:00 that day. What is your destination? Sentence4: I have train TR3544 departing at 19:50 and arriving by 20:07. Would that work for you? Sentence5: ok, perfect, have a great day Sentence6: No that will be all. Sentence7: I'd also like to see some things in town, in particular any sort of boating. Is there anything like that? Sentence8: The Riverboat Georgina doesn't seem to have an entrance fee. Their postcode is cb41as, phone number 07807718591, and address 251a Chesterton Road. Do you need help with anything else? Sentence9: I found no records of an attraction involving boats near Ely. Would you like me to search for something else, or for boats in a different area? Sentence10: I need to go to ely , near a place that has a boat.What is the entrabnce fee ? Sentence11: Yes, what is the price of that train? Sentence12: Yes, please. Also, what is the entrance fee? Sentence13: The price is 3.52 pounds, would you like me to book a ticket for you? Sentence14: Riverboat Georgina is an excellent boat attraction in the north. Would you like the postcode and phone number? Sentence15: Actually, the part of town doesn't matter. I'd just like to take a boat ride or look at some boats, please. Sentence16: The train should go to ely and should leave after 19:15. Question: Who has spoken the sentence 4? (A) User (B) System
A:
Answer: (A) User