You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: How about TR5570 that leaves at 05:32? Sentence2: no thanks for your service i enjoyed Sentence3: Is there anything else I can help you with today? Sentence4: Where are you headed? Sentence5: How about the TR0788 train that leaves at 05:32? Sentence6: Yes, and I'll just need the train id and departure time. Sentence7: I can't imagine why I asked you to book passage. I always buy my own tickets. In any case, thanks ever so much. Sentence8: Booking was successful, the total fee is 35.79 GBP payable at the station . Reference number is : G2JZA2ZE . Sentence9: I will be leaving on Wednesday. Sentence10: Does that train arrive in Cambridge before 17:15? Sentence11: I am heading to Cambridge. Sentence12: I'm looking for a train departing from broxbourne. Sentence13: I will need to arrive by 17:15. Sentence14: TR0788 arrives in cambridge by 06:32. Would you like me to find something closer to arriving at 17:15? Sentence15: What day will you be travelling? Sentence16: Have a great day. Sentence17: Okay. Would you please book 2 tickets for that one? Sentence18: TR5972 leaves Broxbourne Wednesday at 15:32 and arrives in Cambridge at 16:32, The fare is 17 pounds 90. Question: Who has spoken the sentence 2? (A) User (B) System
Answer: (A) User