You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: That is all for now. Thank you Sentence2: I'm open to it, and I suppose the centre will do. But I'd prefer the west side if there is one. Sentence3: That's okay, Cityroomz will work. Can you book it for 3 people for 2 nights starting on Tuesday? Sentence4: Yes I am looking for a Train that departs from Cambridge and arrives at Birmingham New Street. Sentence5: Yes. Please select the first train available after 14:30 and book 3 tickets. then provide me the reference number Sentence6: Reference number is : Z9RFJQ4W . Anything else you need? Sentence7: Booking was successful, the total fee is 225.3 GBP payable at the station. Reference number is : XMBOA4E1 . Can I help with anything else? Sentence8: Would you like to try cityroomz? I can book it for you? Sentence9: I'm so sorry. There are no hotels on the west side that match your requests. Sentence10: Cityroomz is moderately priced and in the centre. Are you open to places that offer free parking, or do you specifically want to avoid it? Sentence11: Thank you for contacting us. Have a great day! Sentence12: I need a place to stay in Cambridge that includes free wifi. I don't need free parking. Sentence13: I will be leaving on Wednesday after 14:30. Sentence14: Ok. When were you looking to leave? Sentence15: Is it in the West? what is the price range? Sentence16: There are 9 trains listed. Would you like tickets for one of them? Question: Who has spoken the sentence 7? (A) User (B) System
A:
Answer: (B) System