Instruction: Determine the sentiment expressed by the user in her review from the provided choices, and respond by selecting one of the available options.

Input:
I had a really painful tight hamstring, no amount of regular stretching worked, so I got this to assist in getting a deeper stretch and it works great.  The book is full of different stretches for all parts of your body.

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