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: I'm headed to cambridge and the train needs to leave after 9:45. Sentence2: I need to take a train on Saturday Sentence3: The Cambridge Book and Print Gallery is a museum in the west area, located at 49 Newnham Road. Sentence4: I have found 149 trains available. Where are you departing from? Sentence5: Sure, the train leaves at 10:24, Reference number is MEFVDBWF . What else can I help with today? Sentence6: I am looking for the Cambridge Book and Print Gallery Sentence7: I would like to depart from stansted airport. Can you book me a train for 3 people and provide a reference number? Sentence8: That'll be everything. Thank you! Sentence9: You are welcome, goodbye. Sentence10: I can help you with that. Where are you headed, and at what time? Question: Who has spoken the sentence 5? (A) User (B) System
Answer: (B) System