Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: Yes, book it for 7 people at 17:40 Sentence2: Ok there are 7 choices. Is there a particular time you'd like to arrive at your destination? Sentence3: not really, it just needs to leave after 17:15. Sentence4: There are plenty of choices starting at 17:40 and leaving every hour onwards. Do you want me to book it? Sentence5: Booking was made, ref number is 6QWLFWW5! Do you need anything more? Sentence6: I'm looking for a train on Sunday that leaves after 17:15. Sentence7: I'll be leaving from cambridge and heading to stansted airport. Sentence8: thats all, see ya! Sentence9: What are your departure and arrival destinations? Sentence10: have a safe trip, bye. Question: Who has spoken the sentence 9? (A) User (B) System
Output:
Answer: (B) System