You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: I am looking for an expensive restaurant that serves Portuguese food. Please also provide the phone number. Sentence2: Yes, could I have their phone number? Sentence3: Thank you! Goodbye! Sentence4: Thank you for using the Cambridge restaurant system. Goodbye. Sentence5: The phone number for Cote is 01223 311053. Sentence6: Cote is a French restaurant located in the centre part of town and is in the expensive price range. Is there anything else I can help you with today? Sentence7: I do not show an expensive Portuguese restaurant. Can I look for something else? Sentence8: How about french food? Question: Who has spoken the sentence 4? (A) User (B) System
Answer: (A) User