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

Sentence1: Where will the taxi be taking you tonight? Sentence2: Please book a taxi for me Sentence3: What time will the taxi be arriving at the Alpha-Milton? Sentence4: You should contact the taxi for an approximate time. Sentence5: Sure! when would you like to arrive? Sentence6: I can definitely help! Where are you departing from? Sentence7: Anytime! Enjoy your stay. Sentence8: I am eager to visit cambridge university botanic gardens. Sentence9: Ok, I've booked your taxi. It will be a grey lexus, contact number 07229148300 Sentence10: I am leaving from the Alpha-Milton Guest House. Sentence11: I want to arrive by 19:00 Sentence12: That is all I need. Goodbye. Question: Who has spoken the sentence 3? (A) User (B) System
Answer: (B) System