Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: I would be arriving Sunday. Sentence2: What day will you be checking in? Sentence3: Ok. The booking was successful. Your reference number is M15ZT8QM . Sentence4: Thank you. That's all I need. Sentence5: Yes, I'd like to book three nights, for three people, at the Worth House hotel. Sentence6: You are welcome. Good bye. Question: Who has spoken the sentence 5? (A) User (B) System
Output:
Answer: (B) System