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

Sentence1: yes the same group of people on the same day at 13:30 please, sorry for being such a pain today Sentence2: El Shaddai sounds interesting. Can you tell me more about it? Sentence3: You're booked at the El Shaddai, ref #XS30YDOA . Can I help you with anything else today? Sentence4: Is that a guesthouse? I would like to stay in a guesthouse please. It doesn't need to have free parking. Sentence5: I am coming to Cambridge and need a place to stay. Is there a hotel in centre with free wifi? Sentence6: Thank you. What is the reference number? Sentence7: actually, i also need a chinese restaurant. Sentence8: You're welcome! Have a great day! Sentence9: You're welcome. Have a great day! Sentence10: Yes, please. I'd like a reservation for 7 people for 4 nights starting on Tuesday. Sentence11: The Lucky Star will fit your needs. Would you like me to make you a reservation? Sentence12: El Shaddai is a cheap guesthouse in the centre of town. the phone number is 01223327978. Can I be of further help? Sentence13: Okay. I have made reservations for 7 at the Lucky Star Restaurant for Tuesday at 13:30. Sentence14: I recommend the university arms hotel on regent street. Would you like me to book your stay? Sentence15: Booking was successful. The table will be reserved for 15 minutes. Reference number is : 3GOBXA42 . Sentence16: Nothing else. Thank you for getting us booked. Sentence17: Ok great, Thank you. That is all that I need. Sentence18: No it isn't. But the Alexander Bed and Breakfast and El Shaddai are both guesthouses that fit what you are looking for. Are you interested? Sentence19: I can help you with that. In what area of town and price range would you like to dine? Sentence20: I am looking for the south side and cheap please. Question: Who has spoken the sentence 12? (A) User (B) System
Answer: (A) User