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

Sentence1: Yes, may I have their phone number and address please. Sentence2: I want to book the Archway House in Cambridge. Sentence3: How people will be staying? Sentence4: We'll be checking in on Monday and will be staying for 3 nights. Sentence5: There will 6 people can you book it and send me the reference number? Sentence6: Of course. The phone number is 01223334900. The address is saint andrew's street. Can I help you with anything else today? Sentence7: I have made those reservations. Your reference number is B3HCU4VS . Sentence8: And what day would you like to check-in? Sentence9: That's all I need! Thanks, bye! Sentence10: You're welcome, glad I could help. Sentence11: how about one that is in the type of college? Sentence12: Christ's college is in the centre of town and their entrance fee is free. Would you like their information? Sentence13: I am also looking for entertainment in the centre of town. Sentence14: There aren't any entertainment spots in the centre of town. Would you like to search for a different type of place or another area? Question: Who has spoken the sentence 5? (A) User (B) System
Answer: (B) System