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

Sentence1: Ok no problem, when would you like the room booked for? Sentence2: Lets try City centre north b and b, if that is not successful, any hotel in the same price range Sentence3: You are very welcome. Thank you for contacting the Cambridge TownInfo centre. Good bye. Sentence4: Hi, I'm looking for a place to stay with free parking and zero stars. Sentence5: Booking was unsuccessful. Want to find another hotel? Sentence6: The A and B was indeed successful and your reference number is II677Z30 . Sentence7: I have 2. City centre north b and b in the north and the el shaddai in the centre. Which one would you prefer? Sentence8: I need it for four people and four nights starting Monday. Sentence9: the el shaddai in the centre Sentence10: Thank you so much for your help. Have a nice day. Bye. Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User