You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Q: Sentence1: Let us know if you need more help, good bye. Sentence2: I've booked 2 tickets for you on TR7656 ref#IBECBEPN . The total cost is 35.79 GBP. Is there anything else I can help with today? Sentence3: Great thanks! That will be all! Sentence4: I am looking to book a ticket for 2 people for the tuesday train leaving from cambridge and arriving by 10:30 at broxbourne Question: Who has spoken the sentence 1? (A) User (B) System
A:
Answer: (B) System