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

Sentence1: No need for a booking, right now. Could you tell me the arrival time? Sentence2: Is there a train I can take from cambridge that leaves after 18:15? Sentence3: it is located in sleeperz hotel, station road Sentence4: No, but I do need free parking and wifi. Also, are there any 0-star places? I'm feeling adventurous. Sentence5: Thank you for contacting the Cambridge TownInfo centre. Goodbye Sentence6: Could you book it for 3 people and 4 nights starting Wednesday? Sentence7: Do you have a specific area in mind? Sentence8: Please give me the correct area of town. Sentence9: the arrival time is 20:06 Sentence10: The TR1006 leaves at 19:00. Would that work? Sentence11: Great, thanks so much, that's all I need! Have a great day! Sentence12: cityroomz is a moderately priced 0 star, but they don't provide parking. It's in a totally sketchy area called Sleeperz. Want to give it a shot? Sentence13: I would like to leave on Sunday and go Leicester. Sentence14: Sure. The TR9517 leaves at 18:21 on Sunday for Leicester. Would you like me to book it? Sentence15: Booking was successful starting wed. Reference number is : N18DU4NR . CityRoomz, sleeperz hotel, station road, cb12tz. Sentence16: I also need a place to stay in the moderate price range. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User