Given the task definition, example input & output, solve the new input case.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
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
Output: Answer: (A) User
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 case for you: Sentence1: NO thanks, no need to book for now. That is all of the info that I need. Sentence2: Moderately priced options in the north are abundant. Do you have any particular preferences or needs I should enter into the system to narrow it down? Sentence3: Ok great. Anything else you need? Sentence4: I would book from acorn guest house, with 4 stars. Is that okay? Sentence5: I am leaving from cambridge to bishops stortford. Sentence6: TR2730 is the train ID. May I go ahead and book that for you? Sentence7: The hotel should be a guesthouse, in the 4 star range Sentence8: That trip would be 10.10 pounds per ticket. Sentence9: Yes, that sounds good. Can you book that for Wednesday. I have 2 people and want to stay 3 nights. Sentence10: Yes, are there any trains leaving town after 13:45 on Friday? Sentence11: Can i have the price as well. Sentence12: The booking was successful. Reference number is : YH1D51ZS . May I help with anything else? Sentence13: Can I have the train ID and price for the first train after 13:45? Sentence14: I'm looking for a moderate priced place to stay in the north part of town. Sentence15: Can we try for 2 nights instead. I'll need the reference number too. Sentence16: No. Do you have any suggestions? Sentence17: Thank you goodbye. Sentence18: I have several trains that will work for you. You can arrive as early as 16:07 or as late as 24:07. Sentence19: Where will you be leaving from and going to? Sentence20: You are welcome, have a great trip. Sentence21: We have plenty of options. Any other preferences? Sentence22: Unfortunately, that booking was unsuccessful. Would you like to try a shorter stay? Question: Who has spoken the sentence 21? (A) User (B) System
Output:
Answer: (B) System