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: Have a nice day! Sentence2: Could I have the phone number, postcode please. Sentence3: Addenbrookes Hospital is on Hills Rd, in Cambridge. Do you need anything else? Sentence4: You as well and thank you for using the Cambridge TownInfo centre. Goodbye! Sentence5: The phone number is 01223245151. The post code is CB20QQ. Is there anything else I can do for you? Sentence6: welcome. at your service next time Sentence7: i want to find a hospital in town Sentence8: No, that's all I need today. Thank you for your help! Question: Who has spoken the sentence 4? (A) User (B) System

Answer: (A) User