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

Example input: 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
Example output: Answer: (A) User
Example explanation: The sentence 1 is said by a user because the intent of it says that the information has to be gathered from the system
Q: Sentence1: I could certainly help you book one if you don't mind that it has internet. Would you like to try the Acorn Guest House? Sentence2: Would you like to book one of those today? Sentence3: I have a train that departs at 21:01 and two more each a hour later than the first. Which train would you like to book? Sentence4: You're welcome. Have a nice day. Sentence5: There are 133 trains making that trip, do you have a day and time you would like to go? Sentence6: Yeah, could you find me a train? I'm in Cambridge, and I'd like to go over to Birmingham New Street. Sentence7: No that sounds perfect. Thank you for all your help. Sentence8: I have 12 guesthouse and 2 hotels in that range. Is there a certain area of town you would like to stay in? Sentence9: No preference on area, but can you see if there are any that have 4 stars? Sentence10: That sounds perfect. Can I have the postcode and phone number please? Sentence11: Okay, let's try that one. Sentence12: Yes, I'd like to leave after 21:00 on Wednesday. Sentence13: I have successfully booked you for the TR7935 train leaving at 21:01. Your reference number is E9ZIOMAN . Sentence14: Great, thank you! I'd like to find a place to stay, too. I'm thinking of something in the moderate range with free parking. Any ideas? Sentence15: Yes, it has 4 stars and includes free parking. Sentence16: I have 3 in the north, 1 in the south, and 1 in the east. Sentence17: Does it have four stars? Sentence18: It looks like all 9 choices do include Internet. Would you be willing to use one of those? Sentence19: I will take the 21:01. the ticket is just for me and I would like a reference number after the booking is completed. Sentence20: What day would you like to book the hotel for? Sentence21: I'll take whichever one doesn't include Internet. Sentence22: Sure, the postcode is cb41da and the phone number is 01223353888. Can I help with anything else today? Question: Who has spoken the sentence 15? (A) User (B) System
A:
Answer: (B) System