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

Sentence1: Yes! City Centre North B and B is an inexpensively-priced guesthouse in the north of town at 328A Histon Road. Would you like to book a room? Sentence2: Certainly! How many tickets would you like? Sentence3: Please book that train for me now. Sentence4: I can find one for you. Can you tell me what day you would like to travel, please? Sentence5: They weren't able to accommodate those parameters. Would you like to try a shorter stay? Sentence6: The train should arrive by 14:45 and should be on the same day as the hotel booking. Sentence7: Great, I recommend train TR5108. It departs at 13:29 and will get you there by 14:07. Would you like me to book it? Sentence8: I am looking for information about the City Centre North B and B hotel. Can you help me with that? Sentence9: I need 6 tickets for the same day. Sentence10: You're welcome! Lovely day to you. Sentence11: That's all I need today, thank you. Sentence12: Great! I also need a train from bishops stortford to cambridge, please. Sentence13: The booking for City Centre North B&B has been made, your reference number is 0FAFY5PP . Sentence14: Booking was successful, the total fee is 48.48 GBP payable at the station . Reference number is : GSTIN0L6 . Sentence15: Sure. Let's try 2 nights. Thanks. I'll need a reference number, too, please. Sentence16: Yes can I book it for 6 people starting on Saturday for 4 nights please? Question: Who has spoken the sentence 10? (A) User (B) System
Answer: (A) User