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

Sentence1: Sure. Your reference number is 6F6ZHY2Z . Is there anything else I can help you with? Sentence2: I am going to need a taxi to go between the two places. I need to arrive by my reservation time. Sentence3: No, not really. Just needs to be in the moderate price range. Sentence4: Hi, I am looking for a 4 star hotel to stay at. Free parking is not necessary. Sentence5: Here is a number for a reliable taxi Sentence6: I'd recommend the avalon hotel. Would you like to book a room? Sentence7: I am also looking for a resturant called Nandos City centre. Can you make a reservation there for 2 people at 17:00 on Saturday? Sentence8: Yes, I would. Can you book it for 2 people for 5 nights starting Saturday? Sentence9: I have several indifferent areas of town. Do you have a location preference? Sentence10: I successfully booked a room for 2 at the Avalon for 5 nights starting Saturday. Your reference number is D5ZO6ZH1 Sentence11: I would prefer to keep it in the moderate price range and I really need free WiFi as well, please. Sentence12: Okay I can help you with that. There are many options to choose from. What is your price range? Question: Who has spoken the sentence 1? (A) User (B) System
Answer: (B) System