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: Booking was successful. The table will be reserved for 15 minutes. Reference number is : PJ7X1NHS . Sentence2: Royal Standard is located at 290 Mill Road City Centre. Would you like to know more about the restaurant? Sentence3: I am looking for a particular restaurant. Its name is called royal standard Sentence4: what about we try booking for Friday? Sentence5: Thank you for using our services. Sentence6: Sorry, looks like there's no availability. Want to try another day or time slot? Sentence7: I'd like to book for 1 person at 1145 on thursday please Sentence8: Ok thank you that is all I needed. Question: Who has spoken the sentence 5? (A) User (B) System
Answer: (B) System