Instruction: Carefully assess the user's review for any strong expressions of sentiment, either positive or negative. Based on your analysis, select the most fitting sentiment option from the provided list as output.

Input:
I've had five of these fans running 24/7 with no problems at all for the past 4 years. You won't go wrong with these units.

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