Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: Yes please. We would like a table for 2 at 18:00 on Saturday. Sentence2: No thank you,I will call again. Sentence3: I am sorry this restaurant is booked would you like to try a different place? Sentence4: I am looking for one that serves Portuguese food and is cheap. Sentence5: We have nine. Do you have a preference as to cuisine or price range? Sentence6: I found one. It is called Nandos. Would you like for me to book it for you? Sentence7: Have a nice day. Sentence8: I am looking for a restaurant in the south. Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User