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: Assess the user's sentiment in the provided review and select the appropriate sentiment option from the list as the answer.

Input:
User Review: I have a&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Pentax-K-5-16-3-MP-Digital-SLR-with-3-Inch-LCD-Black-Body-Only/dp/B0043M6F14/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Pentax K-5 16.3 MP Digital SLR with 3-Inch LCD (Black Body Only)</a>&nbsp;with&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Pentax-SMC-DA-Series-16-50mm-f-2-8-ED-AL-IF-SDM-Wide-Angle-Zoom-Lens-for-Pentax-Digital-SLR-Cameras/dp/B000NO5QV6/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Pentax SMC DA* Series 16-50mm f/2.8 ED AL IF SDM Wide Angle Zoom Lens for Pentax Digital SLR Cameras</a>and&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Pentax-SMC-DA-Series-50-135mm-f-2-8-ED-IF-SDM-Telephoto-Zoom-Lens-for-Pentax-and-Digital-SLR-Cameras/dp/B000NO5QVG/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Pentax SMC DA* Series 50-135mm f/2.8 ED IF SDM Telephoto Zoom Lens for Pentax and Digital SLR Cameras</a>&nbsp;lenses.  I think this is a great set, as I get a huge range out of two quality lenses.  I have been using the wide angle most of the time, probably 85-90%, as I find that it is a good general purpose lens and great for landscapes and most other situations unless a long lens is needed.

However, I had one problem: If I was at a party or social gathering and wanted to take some extemporaneous portraits, the 16-50mm was not working well for me.  For one, it is pretty heavy and bulky to lug around at a party.  Secondly, it is a pretty big piece of glass to point at someone, and it can freak people out a little bit (the lens diameter is 77mm, and if you zoom to 35mm or beyond it telescopes out pretty far, giving the impression that you are getting in really close even when you are not).  A lot of my subjects had a "deer in the headlights" look to them.  Not to mention, it is a $1000 lens with "steal me" written all over it!

That is why I picked up this great little lens.  It is small and unassuming, but wow does it take breathtaking photos.  I have been completely blown away by it.  Don't let the images on Amazon fool you -- it looks plasticky and frankly a little junky on the images they show here, but in person it looks and feels very solid, although indeed there is a fair bit of plastic casing.  With this lens you can sneak up on your friends and get great shots without their even noticing.  The 50mm focal length I find is quite suited to this.  And perhaps most importantly, the f1.4 aperture allows you to take photos in unusually low-light situations without a flash, not to mention remarkable bokeh effects.  In situations where previously I would have left the DSLR at home, I have found myself snapping on this great little lens and bringing it along, and getting some really memorable shots as a result.

Some reviewers here have described this as a good "walk around" lens.  I'm not sure I would go that far, as the focal length is a bit long for my tastes on a DSLR for a lot of situations.  But this is of course depends on your personal style whether you would prefer to use something wider.  For portraits, this is now my go-to lens without question.

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


assistant
Answer: A: very positive