You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: Okay, great. Have a safe trip. Goodbye. Sentence2: Yes please. I need it booked for 1 person for 2 nights starting tuesday. Can i get a reference number? Sentence3: I have found the allenbell guesthouse. It meets all of your criteria, is in the cheap price range, and provides internet and parking. Would you like me to book it? Sentence4: Thank you, that is it for today. Goodbye. Sentence5: The reference number for your booking is KEBFTR7I . Can I do anything else for you? Sentence6: I need a place with rated 4 stars in the east. Can you help me find one that like a guesthouse? Question: Who has spoken the sentence 1? (A) User (B) System
A:
Answer: (B) System