Detailed Instructions: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: I would like chinese food please? Sentence2: Yes I would like to book it for 6 people for 3 nights staring from Thursday and would like a reference number after doing so. Sentence3: I have booked the hotel for you. The reference number is S770N2F9 . What kinds of restaurants are you hoping to try? Sentence4: I have made your reservation for 6 people at 14:00 on Thursday for Charlie Chan. Your reference number is 3QUDNYHJ . Is there anything else I may assist you with? Sentence5: I found several all over town. I can narrow the options down based on what part of town you prefer. Sentence6: book at table for 6 at 14:00 on thursday, please. Sentence7: that sounds good to me. i want you to book it for me Sentence8: I'm coming into town and want to try local restaurants and am looking for a hotel called Bridge Guest House. Do you know where this place is at? Sentence9: I need the reservation for 6 people at 14:00 please. Sentence10: Thank you. That is all I need. Sentence11: I have 10 restaurants available. What price range would you prefer? Sentence12: Okay. I need to know the day, time, and number of people you would like to book a reservation for? Sentence13: I would like to be in the centre Sentence14: A cheap place please. Sentence15: Okay. I've booked a taxi for you. It'll be a yellow lexus and the contact number is 07801886354 Sentence16: Thanks for letting us assist you! Enjoy your visit! Sentence17: What day would you like the restaurant for please? Sentence18: yes it is located in 151 hills road. anything else? Sentence19: how about charlie chan? sounds lovely. Sentence20: Yes I need a taxi leaving the hotel for the restaurant a little before 14:00. Question: Who has spoken the sentence 13? (A) User (B) System
A:
Answer: (B) System