You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1:i need a place to dine in the center thats expensive Sentence2: I have several options for you; do you prefer African, Asian, or British food? Sentence3: Any sort of food would be fine, as long as it is a bit expensive. Could I get the phone number for your recommendation?Question: Who has spoken the sentence 2? (A) User (B) System
Solution: Answer: (A) User
Why? The sentence 1 is said by a user because the intent of it says that the information has to be gathered from the system

New input: Sentence1: There are 70 results. Is there a certain day or time you'd like to leave? Sentence2: May I have the postcode as well ? Sentence3: Find me a train out of Cambridge to london kings cross Sentence4: i also need a place to dine. Sentence5: Yes I have booked that for you and your reference number is E3M7QM9F . Sentence6: You're welcome. Have a nice day! Sentence7: TR1006 arrives at 19:51, would that work? Sentence8: Here you go cb30ad Sentence9: Yes, British food in the West would be great! Sentence10: Great, thanks very much, that's all I need! Sentence11: Saint johns chop house serves british food in the west. Sentence12: I need it on Friday and it should arrive at London Kings Cross by 21:45. Sentence13: I guess that will work. Can you please make a booking for 3 people and when you are through may i also have the booking reference number. Sentence14: 01223353110 is the number. Sentence15: Is there a particular cuisine or location that I can recommend for you? Sentence16: What is the phone number and postcode to Saint Johns Chop House? Question: Who has spoken the sentence 15? (A) User (B) System
Solution:
Answer: (B) System