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: Thank you for using our service, and have a great day! Sentence2: Addenbrookes has a gynecology department! Would you like to call them or book an appointment? Sentence3: No, that's OK, I have everything I need now. Thanks very much for your help! Sentence4: Is the hospital located in town, and what is their postcode? Sentence5: I'm looking for a hospital with a gynecology department. Sentence6: Addenbrookes Hospital is located at Hills Rd, Cambridge, postcode CB20QQ. Would you like the phone number? Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User