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: You are welcome. Call back if you need anything else. Sentence2: The postcode to the hospital is CB20QQ. Sentence3: It's located at Hills Rd. Postcode is CB20QQ. Do you need more information? Sentence4: I'm looking for the Addenbrookes Hospital. Sentence5: No thanks. I just needed the postcode. Sentence6: That's all I needed. Thanks, good bye. Question: Who has spoken the sentence 1? (A) User (B) System
Answer: (B) System