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

Sentence1: I want to book it for 5 people for 2 nights starting on thursday. Sentence2: Thank you! I'm also looking for a train departing from cambridge that leaves on saturday. Sentence3: Hello, we are looking for information about lodgings in Cambridge. Price is no option and we would like a very nice hotel. Sentence4: Okay, you are all set! Reference number is : RGBB7MTN . Sentence5: As long as its insanely expensive and has free parking. Centre located please. Sentence6: Okay, have a good day. Sentence7: I am not sure how many yet. For now, I need the departure time and the length of travel time for TR0823. Sentence8: The departure time is 10:01 and the duration is 60 minutes. Sentence9: I would recommend the university arms hotel. It is in the centre, expensive, and has free parking. Can I help with anything else? Sentence10: TR0823 will have you arriving at 11:01. How many tickets do you need? Sentence11: There are 33 hotels available, do you have any other criteria to narrow it down? Sentence12: What is your destination please and travel time? Sentence13: Ok, that's all I need for now. Thanks, bye. Sentence14: I'm heading to Broxbourne, and I need to arrive by 11:15. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User