Q: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Sentence1: Perfect, thank you. Sentence2: It appears that time is unavailable at this restaurant. Would you like to book the restaurant at a different time, or possibly book at a different location? Sentence3: Not just yet, could you provide me with the travel time for TR8824? Sentence4: TR8824 is to arrive by 19:27, making the duration of the travel time total to 88 minutes. Sentence5: Can you please book that for Friday at 13:15 for 3 people and give me the reference number? Sentence6: Yes I do! It is located in the north and is at a moderate price range level. It serves chinese food. Sentence7: Is there anything else I can help you with? Sentence8: Thank you for using Cambridge TownInfo centre, have a great day! Sentence9: Do you have any information on a restaurant called the Golden Wok? Sentence10: What day and time would you like to leave for London Liverpool Street? Sentence11: No, that's all for today. Thank you again! Sentence12: Thanks. Can you help me find a train to london liverpool street now? Sentence13: I would like to leave after 17:15 on saturday. Sentence14: How about 12:15 on Friday? Sentence15: The first train after 17:15 is TR8824 which leaves at 17:59. There are two later trains that day. Would you like to book one now? Sentence16: Booking was successful! Your table will be reserved for 15 minutes. Your reference number is EL18B6UX . Question: Who has spoken the sentence 4? (A) User (B) System
A:
Answer: (A) User