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

Let me give you an example: Sentence1:i need a place to dine in the center thats expensive Sentence2: I have several options for you; do you prefer African, Asian, or British food? Sentence3: Any sort of food would be fine, as long as it is a bit expensive. Could I get the phone number for your recommendation?Question: Who has spoken the sentence 2? (A) User (B) System
The answer to this example can be: Answer: (A) User
Here is why: The sentence 1 is said by a user because the intent of it says that the information has to be gathered from the system

OK. solve this:
Sentence1: No, that is all, thank you. Sentence2: Yes, if there is one available. Sentence3: I need a restaurant in Cambridge that is expensive and also in the centre of town. Sentence4: Does Bedouin serve German food? Sentence5: Are there any Japanese restaurants in the same area and price range? Sentence6: Great! I'd like to make a reservation for 6 people at 17:15 on Tuesday. And I'd like a reference number, please. Sentence7: Booking was successful. The table will be reserved for 15 minutes. Your reference number is ZMGYWSSO . Is there anything else that I could help you with? Sentence8: I'm sorry I mean to say 9:15. I need to arrive by 9:15. Sentence9: There are 13 trains the latest is an arrival at 18:35 would that work for you? Sentence10: Wagamama is a Japanese restaurant in the centre area in the expensive price range. Sentence11: I'm looking for a train on the same day that arrives by 19:15 and departs from Norwich (going to Cambridge, of course). Sentence12: Yes, please reserve six tickets for us. Sentence13: It's my pleasure! Thank you for contacting us. Goodbye! Sentence14: I don't have any expensive german restaurants in the centre. Sentence15: No, it serves African style food. Would you like to find a restaurant that serves German? Sentence16: Bedouin at 100 Mill Road City Centre meets your criteria. Would you like a booking made for you? Sentence17: I have booked your tickets. The reservation number is 8IIV469O . The fee is 105.6 GBP payable at the station. Is there anything else I can do for you? Sentence18: TR0339 leaves Norwich at 07:16 and arrives in Cambridge at 08:35. Would you like me to reserve your tickets, and if so, how many will be traveling? Question: Who has spoken the sentence 4? (A) User (B) System
Answer:
Answer: (A) User