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

Sentence1: Yes, what type of attraction is Cherry Hinton Water Play? Sentence2: Please book it and send me the confirmation code. Sentence3: Again thank you and have a great day. Sentence4: Thanks I'm also looking for a train that leaves on Thursday. Sentence5: Just one seat. Sentence6: OK, what are your departure and arrival stations, and what time do you want to travel? Sentence7: Before i book it, could you confirm the number of seats you need? Sentence8: You're welcome! Is there anything else I can help you with? Sentence9: It is a park. Sentence10: Excellent, I can't wait to visit it! Thank you. Sentence11: I am looking for information about the the Cherry Hinton Water Play Sentence12: excellent, have a great day! Sentence13: I'd like to go to Cambridge via Broxbourne. I'd like to leave on Thursday and arrive no later than 12:00. Sentence14: That is a free park on the east side of town. They are located at Cherry Hinton Hall on Cherry Hinton Road. Their phone number is 01223446100. Sentence15: I have on that arrives at 11:32. Would you like me to book that for you? Sentence16: Perfect thanks for the help thats everything I need! Sentence17: Well I glad i can help enjoy your stay ! Sentence18: Your booking was successful! The reference number is 698RE4W1 . The total fee of 17.89 is payable at the station. Question: Who has spoken the sentence 17? (A) User (B) System
Answer: (B) System