Given the task definition and input, reply with output. You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: Hakka and The Hotpot are both expensive Chinese restaurants on the north side of town. Would you like a table at one of these? Sentence2: You're welcome! Thanks for using our services. Sentence3: Yes please book the train for 23:29. Sentence4: Unfortunately, I'm not seeing any Vietnamese restaurants in the north. Would you like to try a different area or type of cuisine? Sentence5: There are 2 trains that fit this request. One at 21:29 and another at 23:29. Did you want me to book one of them for you? Sentence6: I am looking for a Saturday train departure from Cambridge Sentence7: That'll be everything. Thank you! Sentence8: How many tickets do you need? Sentence9: How about a Chinese restaurant. Ideally expensive. Sentence10: No, but I need to find a restaurant. It should serve vietnamese food and it should be in the north. Sentence11: I don't need a booking, but can you tell me the train ID, travel time, and arrival time of that train? Sentence12: I've booked that for you. The reference number is ZAV4B1D8 . What else can I help you with? Sentence13: What destination would you like me to look for? Sentence14: I'm hoping for a train to bishops stortford after 21:15. Sentence15: I'd like to reserve a table for 3 at The Hotpot for 10:00 Saturday. I'll need a reference number as well. Sentence16: TR0123 is the train ID. It leaves at 23:29 and arrives at 24:07. Did you need any more information about the train? Question: Who has spoken the sentence 10? (A) User (B) System
Answer: (A) User