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

Sentence1: I'd like to book table at the royal spice for 6 people at 19:45 Tuesday. Sentence2: I was able to book your taxi. You will be in a White Skoda. If you need to contact them, the number is 07145741426. Can I help with anything else? Sentence3: There are many matches to your request. Do you have a preference in area or star rating? Sentence4: I have 11 guesthouse hotels fitting this criteria. Do you have any other preferences? Sentence5: I would prefer a 4 star guesthouse please and I'll need the area and address please. Sentence6: The booking was successful and the table will be reserved for 15 minutes. Your reference number is EQ2EWQ22 . Sentence7: I have no preference for area but I am looking for something with a 4 star rating and moderately priced. Sentence8: I recommend Acorn Guest House in the north. The address is 154 Chesterton Road. Would you like me to book it for you? Sentence9: No, no other preferences. What would you recommend? Sentence10: Ok, can you send me the address and area of Aylesbray lodge? I am also looking for a restaurant called royal spice. Sentence11: Aylesbray Lodge is in the south part of town and the address is 5 mowbray road. Sentence12: No that's all I need. Thank you! Sentence13: Can I book a taxi from Acorn Guest House to Aylesbray Lodge? It needs to get there by 19:45 Tuesday. Sentence14: I'd like a place to say that is a guesthouse type, and includes free wifi. Sentence15: Aylesbray lodge guest house matches your criteria. Would you like me to book that for you? Sentence16: You are welcome. Please let me know if I can be of any other assistance. Enjoy your visit. Sentence17: I prefer something a little more south. Sentence18: There are 11 matches that fit your criteria. Do you have any other preferences? Question: Who has spoken the sentence 7? (A) User (B) System
Answer: (B) System