Detailed Instructions: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: Certainly. Can you please tell me the location you are departing from and where you would like to go? Sentence2: I have train TR9831 leaving at 19:21 and arriving at 21:06. Would that suffice? Sentence3: I will be going to leicaster from cambridge, departing after 18:45 please Sentence4: It was a pleasure to help. We hope you will use our service again in the future. Have a wonderful night. Sentence5: That's all that I needed today, thank you! Sentence6: Yes, that will work out great. Can you please book me 7 tickets for that train? Sentence7: Okay, I've booked 7 tickets for that train. The reference number is STM2J29A . Is there any other information you need? Sentence8: Would you be able to find me a train leaving on Sunday? Question: Who has spoken the sentence 7? (A) User (B) System
A:
Answer: (B) System