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

Input:
I have been using this trackball for over a decade, and it still works as well as when I got it. It's an amazing piece of hardware. The only negative is that it's a pain to clean. The newer models have a "drainage" hole under the ball to minimize dust on the sensors. If I could have this exact model but with the drainage hole, I'd be in heaven. Hmm... is that a Dremel I hear calling?

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