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: I can't wait to try it. I'm not ready to make a reservation yet. Thanks for your help. I'll call back. Goodbye. Sentence2: I am terribly sorry there aren't any, another type perhaps? Sentence3: I have train TR1575 that leaves at 15:09 and arrives in Cambridge at 16:54. Would that work for you? Sentence4: I need information about a train. Sentence5: Yes there are 4 results. How about hotel du vin and bistro? Sentence6: How about european food then? Sentence7: That one is a moderately priced restaurant. It's fantastic! Sentence8: Okay! Where would you like to go? Sentence9: Thanks, I need to find a danish restaurant in the centre of town Sentence10: I have booked you for 3 people on TR1575. Your reference number is Y4IU29UM . Can I do anything else for you? Sentence11: I need a train on thursday that'll arrive by 18:00, traveling from leicester to cambridge. Sentence12: Yes, can you please book me for 3 people and get me a reference number? Sentence13: What is the price range for hotel du vin and bistro? Sentence14: Thank you, we'll be happy to help when you're ready to make a reservation. Have a great day! Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User