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

Let me give you an example: 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
The answer to this example can be: Answer: (A) User
Here is 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

OK. solve this:
Sentence1: Yes, I'd like to arrive by 15:15. I'm leaving from Cambridge as well. Sentence2: Yes, I need the train ID, please. Sentence3: I only need one ticket, please. Sentence4: Ok great and what day would you like the booking to be made for? Sentence5: Yes I was able to book that for you and your reference number is YTANICP1 . Sentence6: I can help with that. I have 10 different trains that can get you there. Did you have a time you need to leave or arrive by? Sentence7: Glad to be of help. Good day to you too. Sentence8: Need a train leaving monday to bishops stortford. Sentence9: Yes I am also looking for somewhere cheap to eat in the centre that serves italian food please. Sentence10: The same day as the train which is Monday. Sentence11: Sure, what time are you looking for a reservation at? Sentence12: Pizza Hut City Centre sounds fine. Could you book a table for 7 people there for me? Sentence13: The total will be 10.10 GBP which is payable at the station. Your reference number is 1EJQJWS2 . Is there any other help you need? Sentence14: There is one leaves at 13:29, arriving at 14:07. Would you like a reservation on that? Sentence15: The ID is TR4861. How many people would you like tickets for? Sentence16: There are three possibilities. Pizza hut city centre, ask or zizzi cambridge. Would one of those work? Sentence17: Awesome! That will be it for tonight. Have a good day. Bye. Sentence18: It'll be for 10:45. Question: Who has spoken the sentence 17? (A) User (B) System
Answer:
Answer: (B) System