Task: Sentiment_Analysis

system
You are a helpful assistant. The assistant first thinks about the reasoning process in the mind by using Belief-Desire-Intention (BDI) framework and then provides the user with the answer. The reasoning process and answer are enclosed within <think> </think> and <answer> </answer> tags, respectively. 
Below is an instruction that describes a task. After thinking, when you finally reach a conclusion based on the customer's intention, desire and belief, clearly state the BDI thinking process within <think> </think> and then the answer within <answer> </answer> tags.


user 
Instruction: Analyze the user's review text and determine the overall sentiment expressed, then choose the corresponding sentiment option from the provided list (A: very positive, B: positive, C: neutral, D: negative, E: very negative) based on the identified sentiment.

Input:
User Review: I just threw away this trackball after around 3 years of use. More on that later.

Ergonomically, this trackball is not as good as the discontinued Logitech Trackman Marble FX, but what trackball is? The Trackball Explorer places your hand in a more horizontal position than the Logitech's more natural/neutral position.

The buttons are placed somewhat poorly. Any time you have to click both mouse buttons, you have to move your thumb forward into an awkward position, and I often hit the scroll wheel while trying to click on the right or left mouse button. The thumb simply should not be asked to do that much, it's not dexterous enough (and I have a lot of training in piano, my thumb is plenty dexterous).

The fourth and fifth buttons are placed well for your fourth and fifth fingers, and the trackball itself is within easy reach of your index and middle fingers.

I know it sounds like I'm ragging on the design a lot, but that's only because I'm comparing this to my previous trackball, the aforementioned Logitech. Compared to most other trackballs, the Trackball Explorer is quite good.

Like most optical trackballs, you still needed to clean it occasionally for smooth scrolling, but the process is quick and easy.

My biggest gripe with this product is that the left mouse button broke after only 3 years of use, which is why it is currently sitting in my trash and my old Logitech is back on my desktop (I abandoned it strictly for not having a scroll wheel, its only flaw).

The left mouse button is attached to the housing by two long plastic tines. One of the tines broke so that getting a click to register became difficult and any clicking inevitably engaged the scroll wheel (either clicking it or scrolling things up and down). This resulted in all kinds of odd behavior from the trackball until I took it apart and figured out what went wrong.

Of all the modern trackballs that have not been discontinued, are not wireless (what the heck is the point of a wireless trackball?) and has a scroll wheel, this is my favorite, but I'm not sure I want to buy another one since the mouse button broke after only 3 years. I've never had a mouse button break before.

*sigh*

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


assistant
Answer: C: neutral