Instruction: Given the user's review, identify the user's sentiment from the listed options. Answer using one of the options.

Input:
There are several problems with this trackball:
1. The shape of the trackball contours your wrist downwards. This can be a major problem for those of us who buy trackballs to save our wrists.
2. The design of the trackball is generic, meaning it is just as usable for lefties as righties. Downside? It doesn't work for either very well. The position of the ball itself puts a lot of strain on the index finger, while the side buttons are too far apart to be easily useful.
3. The wheel is placed in the dead center of the trackball, which puts it just below the palm when using the device. Therefore the only way to use the wheelie function is to move your hand down and place your fingers on the wheel. This almost completely negates the usefulness of the wheel. (The wheel is also stiffer than I was used to)
4. Last and worst, the trackball itself jammed up a great many times on me. I could still make large movements across the screen, but getting the pointer to anything small on the screen took a lot of effort -- and effort is not what you want in a trackball.

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