Given the task definition and input, reply with output. You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: I'd like to find hotels in the cheap price range that offer free wifi. Sentence2: There is one hotel that matches your search. It is the cambridge belfry in the west area. Can I book that for you? Sentence3: There are 2 choices - would you prefer indian or Italian food? Sentence4: No thank you, just the address and phone number please. Sentence5: Thanks. I am also looking for a place to eat in the north. Same price range as my hotel. Sentence6: da vinci pizzeria serves italian food it is in the north of town Sentence7: I would prefer italian. Sentence8: OK, I will need to make a reservation for the same group of people at 12:45 on that same day. Sentence9: It was my pleasure, enjoy the rest of your day. Sentence10: Can you book it for me. 3 people, 4 nights, Sunday. Reference number, please. Sentence11: Great. Thank you for your help. Sentence12: You're all set. Your Reference number is : 7J5INWLY . Can I assist you with anything else? Sentence13: They are located on back lane, cambourne. Is there anything else I can help you with? Sentence14: Booking was successful.Reference number is : 1CU5LU5X . is there anything else i can help? Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User