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: Yes please, for Thursday, 7 people at 16:45. I also need a reference number. Sentence2: Booking was successful. The table will be reserved for 15 minutes. Reference number is : 2FX5XCUM . is there anything else i could help you with? Sentence3: It doesn't matter but it should be expensive and it should be in the centre. Sentence4: Yes, we would like American type food. Sentence5: Sure, what kind of restaurant? Sentence6: Okay and what time would you like to arrive? Sentence7: We actually have different categories of american food -- latin american, modern american, north american, and "the americas." Which of these would you prefer? Sentence8: How about latin america? Sentence9: I'd like to depart Cambridge after 21:30. Sentence10: How about North American cuisine instead? Sentence11: That is all I will need. Thank you. Sentence12: I'm sorry. I have no results that meet your criteria. Would you like to try a different food type, price range, or area? Sentence13: excellent, have a great day! Sentence14: Gourmet Burger Kitchen is expensive and in the center. Would you like to book a table? Sentence15: Yes please book that for me. Sentence16: I also need a train. Going to Ely Friday. Sentence17: Booking was successful, the total fee is 4.4 GBP payable at the station .Reference number is : ZC86HRQ4 . is there anthing else i can do? Sentence18: The train TR9842 is leaving Cambridge on Friday at 21:50. The cost is only 4.40 pounds and the travel time is 17 minutes. Would you like me to book? Sentence19: I am looking for information in Cambridge. looking for a restaurant. Sentence20: Do you have any cuisine preferences? Question: Who has spoken the sentence 5? (A) User (B) System
A:
Answer: (B) System