You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: I have 5 choices for you. If I might suggest the Holy Trinity Church. It has the most unique architecture in our area. They also offer free admission. Sentence2: I will be visiting the centre. Sentence3: Like I mentioned, Holy Trinity Church is totally free. Is there anything else you'll be needing today? Sentence4: Sounds great. Do you happen to know the entrance fee for it? Sentence5: OK I HAVE 1 TRAINS THAT LEAVE AROUND THAT TIMES ONE AT 21:39 WOULD THAT WORK FOR YOU ? Sentence6: I need a train that lease from London Liverpool Street on Tuesday. Sentence7: Yes as long as it leaves AFTER 20:45 that will be fine. How much is it and how long is the travel time? Sentence8: There are 10 days departing London Liverpool Street on Tuesday. Is there a certain time of day you need to travel? Sentence9: No, I don't think so! Thank you for your help! Sentence10: How about architecture type instead? Sentence11: Thank you for using Cambridge TownInfo centre. Please remember us for all of your future travel needs. Sentence12: Which area are you interested in visiting in town? Sentence13: I would like to leave after 20:45. Sentence14: the train ride is 88 minutes and the cost is 16.60 pounds. it leaves at 21:39 and your reference number is Q6UN1GVR . is there anything else i may help you with? Sentence15: There is no entertainment in the centre. Would you be interested in a different type of attraction? Sentence16: I am looking for places to go in town. What type of entertainment is there in the centre? Question: Who has spoken the sentence 4? (A) User (B) System
A:
Answer: (A) User