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

Sentence1: thank you for helping Sentence2: I also need a taxi from my room to the restaurants by the time of my reservation. Sentence3: Booking was successful. Reference number is : VDQW6MG8 . What else can I do to assist you today? Sentence4: You're most welcome. Can I help you with anything else today? Sentence5: I don't know if you've heard of it but can you please get me some information on the la tasca restaurant? Sentence6: I would like to book the Acorn for 2 people for 5 nights starting Sunday. Sentence7: Great! will you please book that for 2 people at 17:30 on Sunday? Sentence8: Happy to help - la tasca is a Spanish restaurant with a moderate price point located in the centre. Sentence9: I need a place to stay, a hotel in the north. Preferably in the guesthouse category Sentence10: Acorn guest house is available, would you like to stay there? Sentence11: OK, it was a pleasure helping you. Have a great time in Cambridge. Goodbye. Sentence12: No that was everything, thank you! Sentence13: Does that include wifi? I don't want it to be too expensive. Sentence14: Booking is complete. I have you booked with a black Audi. Contact number 07873880008. It will pick you up at 17:15. Is there anything? Sentence15: Alright, the table will be reserved for 15 minutes. Your reference number is: AO0MS4Q3 . Sentence16: It does include wifi. It is moderately priced. Question: Who has spoken the sentence 12? (A) User (B) System
Answer: (A) User