Instruction: Assess the user's sentiment in the provided review and select the appropriate sentiment option from the list as the answer.

Input:
I had finally decided to hurl my newly upgraded Windows Vista pc out the window, when I found this little item. Vista flatly refused to recognize any adapter I tried, even though the "Upgrade Assistant" had assured me all was well. This worked INSTANTLY and is fast, reliable and cost-effective.

Options:
A: very positive
B: positive
C: neutral
D: negative
E: very negative
Answer: A: very positive