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 don't know yet. Do you know how much it will cost? Sentence2: Nah. Can you just book me a table at your favorite one? 2 people at 20:45 on Monday, please. Sentence3: Thank you very much for the help. Good bye! Sentence4: Yes, 14:45. Could you give me a departure time that meets my criteria? Sentence5: I would like the reference number if it s successful please. Sentence6: The reference number is 2DNK6C4B . Sentence7: Any arrival time in mind? Sentence8: How about 19:45 and give me a reference number Sentence9: Could you be more specific on where you are departing from and what day you want to travel? Sentence10: I was not able to book a table at 20:45. Would you like to try another time? Sentence11: Thank you. Goodbye. Sentence12: What train should I take to get to Cambridge by 14:45? Sentence13: One moment while I try to make the reservation for 19:45. Sentence14: There are several choices. Do you have a specific price range? Sentence15: Tickets are 16.60 pounds Sentence16: Depart from london liverpool street and should leave on monday. Sentence17: Okay. I am also looking for a restaurant. Are there any restaurants in the centre that serve asian oriental food? Sentence18: Yes, TR7040 leaves at 11:39 and arrives by 13:07. Would that work for you? Question: Who has spoken the sentence 7? (A) User (B) System
A:
Answer: (B) System