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: Nandos is a Portuguese restaurant, it is in the cheap price range, and is on the south part of town. Would you like the phone number? Sentence2: That is all I need. No further questions. Sentence3: You're welcome. Good bye. Sentence4: I would like a restaurant that serves portuguese food Sentence5: OK. Good bye. Sentence6: Cambridge Leisure Park Clifton Way. Can I help you with anything else? Sentence7: what is their address Sentence8: Thank you goodbye. Question: Who has spoken the sentence 5? (A) User (B) System
Answer: (B) System