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: Thank you! Sentence2: Can you book me a table for 7 people at 12:00 on saturday? Sentence3: You're welcome Sentence4: Thanks so much! Sentence5: Thanh Binh is a restaurant serving Vietnamese food in the cheap price range. Sentence6: Okay, got it. Your table has been reserved. The reference number is U2OY8B4T . Sentence7: Thank you have a great day. Sentence8: Hi I need to find a place to dine serving Vietnamese food in the cheap price range. Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User