You will be given a definition of a task first, then some input of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: Sounds great! Could you book it for 1 person for 5 nights starting Wednesday? Sentence2: How about changing that to a 4 star rating? Sentence3: Booking was successful. Reference number is : 34P1OHBR . Do you need any other help today? Sentence4: No preferences on the area, but I want to book it for 1 person for 5 nights starting from wednesday. Sentence5: That we have! Do you have a preference on the area? Sentence6: You're welcome and thanks for using our help desk. Goodbye. Sentence7: Hello Cambridge Towninfo Center representative. I desire a place to stay that 5 stars, cheap and includes free wifi. Can you help? Sentence8: I'm sorry but I'm not finding anything that matches your criteria. Can I help with something else? Sentence9: How does the Alexander bed and breakfast in the centre sound? Sentence10: That is it, thank you for your help. Goodbye Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User