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

Sentence1: Sorry, you'll need to be more clear on your departure site please. Is there a specific hotel you're looking for? Sentence2: Will that be to or from the club and what time? Sentence3: I want to leave the hotel by 05:00. Sentence4: Ballare, a beautiful new nightclub just opened up in the center. Entrance is just 5 pounds, would you like more information on Ballare? Sentence5: You are welcome have a great stay. Sentence6: Alexander Bed and Breakfast meets your requirements. Can I book a room for you? Sentence7: Any type will do, as long as its in the centre. Can you recommend something? Sentence8: i need places to go in town Sentence9: We have museums, colleges, and interesting architecture, as well as many other choices in the center of town. Sentence10: The postal code is cb23na and the address is heidelberg gardens, lion yard. Can I assist you further? Sentence11: Yes, sorry for the confusion. I want a taxi to pick me up at the hotel at 05:00 and my destination is Ballare. Please give me car type and contact number Sentence12: What did you have in mind? Sentence13: Yes, can I have their address with postcode? Sentence14: I am looking for a guesthouse if there is one? Sentence15: It seems like you are asking for a taxi. Where are you departing from and where is your destination, please? Sentence16: Do you happen to have any entertainment places in the centre of town to visit? Sentence17: I have 4 locations in the centre of town with free parking and WiFi. Would you like to book one? Sentence18: Something in the same neighborhood, and that has wifi and parking. Sentence19: Thanks so much you have been a great help to me. Sentence20: Yes, can I please have car type and contact number? Sentence21: Yes on Friday. I need a taxi too. Sentence22: Your all set a blue bmw will be picking you up at 5 the contact number is 07398420565, is there anything else today? Question: Who has spoken the sentence 19? (A) User (B) System
Answer: (B) System