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: There are 5 trains meeting that criteria. Would you like me to book you a ticket? Sentence2: Can you please tell me what your destination is for that trip? Sentence3: Thank you for contacting the help desk. Please, if you have any more questions, do not hesitate to ask. Sentence4: That's perfect. I'd like to book that restaurant for just myself at 10:00 on the same day. Could I get the reference number as well, please? Sentence5: How about Portuguese cuisine at Nandos? Would you like any more information about them or assistance booking a reservation? Sentence6: Yes, I would like to book the ticket now, could I please have the train ID? Sentence7: I would like to depart from Cambridge and arrive at Stevenage, please. Sentence8: I can take care of that myself. Can you also help me find a place to dine in the south, priced cheaply please. Sentence9: OK, you have a table for 1 at 10:00 on Saturday at Nandos. Your reference number is 3JRN2T9Y . Can I help with anything else today? Sentence10: I am all set. Thanks! Sentence11: The train ID is TR8813, how many tickets would you like to book? Sentence12: I need a train that leaves after 13:30 saturday afternoon please. Question: Who has spoken the sentence 11? (A) User (B) System
Answer: (B) System