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 always struggled with a sore lower back.  In an effort to try to get relief, I have tried pills, stretching, physical therapy, etc.  All work to some extent, but each has it drawbacks.

Yesterday, I got this table and tried it out.  I was surprised that after my first "inversion" of only about a minute (the directions say to only go for 15-20 seconds the first time, but what can I say, I'm a rebel :)).  Today I used it again for about a minute, and my back really does feel better.

In addition to back pain relief, it is also a lot of fun.  It is by far the easiest possible way to get the feeling of doing a headstand.

Set-up was fairly simple using the tools provided.  It took a friend and I 10 minutes, but I bet some people could do it in less.

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