You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: I would like to leave after 13:45. Sentence2: No thanks, I just needed the travel time for the train departing at 15:00. Sentence3: The travel time for TR 9386 is 51 minutes. Sentence4: There is a train that leaves at 15:00 would you like me to book that train for you? Sentence5: Ok. Will you be departing from Cambridge? Sentence6: Yes, Cambridge and I want to leave on Sunday. I need travel time Sentence7: Hello, I'm looking for a train to get me to london kings cross. Sentence8: Travel time is 51 minutes. What time were you hoping to leave? Sentence9: Thank you for using Cambridge TownInfo centre, goodbye! Sentence10: Thanks, that's all I needed. Goodbye! Question: Who has spoken the sentence 4? (A) User (B) System
A:
Answer: (A) User