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: ok, what's their address and postcode? Sentence2: I also need a taxi. Sentence3: How about the avalon? Sentence4: excellent, have a great day! Sentence5: Camboats address is The Plough, Green End, Fen Ditton and their postcode is cb58sx. Sentence6: Great, if they can book for 6 people for 5 nights, starting on Wednesday. Can you try that for me? Sentence7: That would be just fine, thank you. Sentence8: I want to leave by 15:30. Sentence9: I'd be happy to help with your request, first I'll need to know your departure site and destination and what time you're looking for. Sentence10: If you're going to the east, I recommend taking a boat ride with Camboats. Sentence11: It will be a blue Tesla. You may contact them at 07008080625. Sentence12: Any area will do. Recommend something. Sentence13: All the moderately priced, 4-star accommodations are guesthouses. Is that OK? Sentence14: Which are would you like? Sentence15: I need to know a departure and/or arrival time. Sentence16: Thank you! Are there any places to go in the east? Sentence17: Thank you very much. That is all that I need. Sentence18: Can I get the contact number and the car type please? Sentence19: What is the cost? Sentence20: I was able to complete that booking for you. Your confirmation number is O4E7TJ08 . Sentence21: I will want to go between the attraction, and the hotel. Sentence22: I am looking for a moderately priced 4 star hotel. Question: Who has spoken the sentence 20? (A) User (B) System
Answer: (A) User