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: Yeah. The reference number is CVWAKCN2 Sentence2: Is one of them in the cheap price range? Sentence3: Yes, I'd like to book a taxi to go from the attraction to the restaurant. Sentence4: I'd be happy to find you a taxi, but first I will need to know what time you'd like to leave corpus christi. Sentence5: I don't mind an entrance fee. Could you actually give me the postcode for that college? Sentence6: Is an entrance fee okay? If so, the corpus christi college located at king's parade. Fee is 2 pounds. Would you like the phone number? Sentence7: I have booked you a taxi that will get you to the restaurant by 11:30. Their phone number is 07469156027. Is there anything else I can help you with? Sentence8: Yes. Can you please search for an attraction in the type of college? Sentence9: I've got three that fit that bill... the gardenia, la mimosa, and shiraz. Do you have a preference? Sentence10: I am sorry. There does not seem to be any matching your choices. Would you like to try another area or attraction? Sentence11: I would like to leave Corpus Christi College in enough time to arrive at the restaurant at the booked time of 11:30. Sentence12: Great, could I book a table of 5 for 11:30 on wednesday? If so, please provide me with a reference number. Sentence13: I'm looking for a Mediterranean restaurant near the centre of town. Sentence14: Thank you! Is there any entertainment in the same area as the restaurant? Sentence15: Yes, The Gardenia. Sentence16: Great! I'm glad I could be of assistance to you. Thank you for using our service. Sentence17: What is the car's contact number and type? Sentence18: Your taxi is a Black Audi and their contact number is 07469156027. Is there anything else I can help you with? Sentence19: That's everything, thank you! Sentence20: Corpus christi is located at king's parade, postcode cb21rh. Would you like any further information? Question: Who has spoken the sentence 11? (A) User (B) System
Answer: (B) System