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

Sentence1: The Gonville is expensive. Sentence2: Can you book it for me and get a reference number ? Sentence3: I want to book for 2 people and 3 nights starting Sunday. Sentence4: Boom!! We have gonville hotel. Need me to book a room? Sentence5: Your booking for Sunday at the Huntingdon Marriott Hotel has been booked. Your reference number is KKV2OAGC . Sentence6: Great, you're all set. Your reference number is : LEX7I9AY . Anything else I can help with today? Sentence7: No thanks. You've been very helpful. Take care. Goodbye. Sentence8: I'll be more than happy to help you book a room as soon as you tell me what part of town you prefer. Sentence9: I have 3 hotels that meet that criteria. All are 4 star rated and offer free parking and free internet. I have 2 in the west and 1 in the centre. Sentence10: Can you tell me your departure and destination locations please? Sentence11: You are welcome. Goodbye. Sentence12: I'm going from cambridge to broxbourne after 20:00 on monday. Sentence13: I need a place to stay. Find me a hotel with free wifi. Sentence14: No, only 3 stars. Sentence15: That would be great, do you know what the price range is? Sentence16: Huntingdon marriott hotel comes highly recommended, shall I book your room there? Sentence17: Great I also need a train please. Sentence18: There's a train at 20:01 that will get you to Broxbourne at 21:01. Would you like to book passage? Sentence19: I was hoping for something with at least 4 stars. Sentence20: Yes, two tickets please Sentence21: Does that have a 5 star rating? Sentence22: I don't have a preference for side of town. Question: Who has spoken the sentence 1? (A) User (B) System
Answer: (B) System