You will be given a definition of a task first, then some input of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: Oh they really are lovely. And the number is 01223464646. Sentence2: That sounds lovely. What's their phone number? Sentence3: I was able to book the table for eight on Tuesday 11:00. The reference number is R8O6B9DF . The table will be reserved for 15 minutes. Sentence4: I'm looking for places to go in town. Can you search in the area of south? Sentence5: Thank you for using our service. Have a great day! Goodbye. Sentence6: We only have one listing for an Italian restaurant in the south. It's located at Cambridge Leisure Park Clifton Way Cherry Hinton. Does this interest you? Sentence7: Thank you so much. You took care of everything. Thanks. Bye. Sentence8: I was able to book a black honda contact number is 07790378961 Sentence9: Thank you. I am also looking for an expensive Italian restaurant. Sentence10: Absolutely! When would you like to arrive at or leave by? Sentence11: We have several great options. The Byard Art museum is popular and has free admission. Sentence12: I'd like to get to the restaurant by my reservation time. Sentence13: I'd like one near the museum in the south. Sentence14: Yes. I need a table for 8 at 11:00 on Tuesday. Sentence15: Thank you, can I also get a taxi between the two places? Sentence16: Sure, there are 5 expensive Italian restaurants for you to choose from. Is that a specific area you would like the restaurant to be in? Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User