You will be given a definition of a task first, then some input of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: You're quite welcome! Thanks for contacting the Cambridge TownInfo Centre and have a great day! Sentence2: I was able to reserve a table. Your reference number is 2SLK6U5L . Is there anything else you'd like me to do? Sentence3: No, I think that covers everything. Thanks so much for your help! Sentence4: Sounds great. Please book a table for 3 at 20:00 on Friday and give me the reference number. Sentence5: There are restaurants that serve british food. What is your price range? Sentence6: There are 3 expensive restaurants in the centre of town that server British food. I would recommend the Midsummer House Restaurant. Sentence7: I want to eat fine british food. Sentence8: I like expensive restaurants and would prefer something in the city centre. Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User