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: The postcode is CB20QQ. Do you need specific department information? Sentence2: I need the postcode please. Sentence3: Where is Addenbrookes Hospital? Sentence4: Thank you goodbye Sentence5: No, that is all I need, thank you. Sentence6: Addenbrookes Hospital is located on Hills Rd, Cambridge. Do you need the phone number? Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User