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 have used tiffen filters for years & once had to deal with customer service because of an error I made.  They were great!

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