You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: Great can I also get a train going to leicester and arriving by 11:45? Sentence2: Do you just need the one ticket, or will others be travelling with you? Sentence3: I'm looking for a gastropub in the east. Sentence4: TR5677 will arrive at 11:06 would that work for you? Sentence5: Ok great. Would you like for me to go ahead and book the train for you? Sentence6: 105 minutes. 30.24 pounds. Sentence7: Cambridge, and I will be traveling on Saturday. Sentence8: Can you give me the travel time and total cost please? Sentence9: Could you get me the price of that train and the travel time before you book it? Sentence10: No just the one. Thank you. Sentence11: I have TR5677 arriving at Leicester by 11:06. Sentence12: Your booking was successful, the total fee is 30.24 GBP payable at the station . Reference number is : LV1BEG9R . Sentence13: I am glad I was able to help. Have a wonderful trip. Sentence14: Could you please provide the phone number, address and postcode for The Royal Standard? Sentence15: ok thank you so mucy Sentence16: Yes, please book the train for me. That will be all. Sentence17: The Royal Standard is a gastropub located in the east. Sentence18: Where will you be departing from and what day would you like to travel? Sentence19: Phone Number: 01223247877. Post Code: cb13nl, address 290 Mill Road City Centre. Anything else? Sentence20: Thank you so much! That's all I need. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User