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: Hello, I'm looking for a hospital in town. Sentence2: Addenbrookes Hospital is on Hills Rd, Cambridge. Is there a particular department you need? Sentence3: No, I just needed the address. Good bye. Sentence4: Thank you for calling the TownInfo centre. Goodbye. Question: Who has spoken the sentence 3? (A) User (B) System
Answer: (B) System