You will be given a definition of a task first, then some input 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: There are 19 trains. Do you have a preferred time to leave or arrive by? Sentence2: We have thanh binh. Would you like a reservation? Sentence3: Great. Thank you for all your help. Sentence4: I am departing from Cambridge and going to Birmingham New Street. Sentence5: Booking was successful. The table will be reserved for 15 minutes. Reference number is : LAKQV5EK . Sentence6: I also need a Friday train. Sentence7: I want to arrive at Birmingham new street by 21:15, please. Sentence8: OK, from where to where do you need a train? Sentence9: Find me a cheap vietnamese food place please. Sentence10: Yes please pick the last option and book 8 tickets for me. I will definitely need the reference number too. Sentence11: Your booking was successful. The reference number is Z277D99H . Sentence12: You are welcome, let us know if we can help with anything else. Sentence13: Yes, please book a table for 8 on Thursday at 15:00. Sentence14: There are 15 possible options. Do you want me to reserve some tickets for you? Question: Who has spoken the sentence 3? (A) User (B) System
Output:
Answer: (B) System