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:
Fantastic whistle for a variety of uses. I referee soccer and work as a lifeguard, and I have used Fox 40's in both capacities. It takes some lung power to blow, which can be a downside for people who are not familiar with it, but when used correctly it produces an extremely loud, piercing tone that is very hard to miss. I personally prefer it for soccer over lifeguarding; I use a Whistles for Life Tri-Power for guard work, but this is great for soccer because of the distinctive tone that is easily heard. They're great for full-field games because of the loud tone, but they're a bit much for smaller fields, and you want to be careful that you're not too close to a player when you blow it (otherwise you may hurt their ears, especially with younger players). I swear by these whistles.

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