CISSP Practice question 1 for domain 1

I have seen thousands of question in the last two decades. I want to share with you what I have learned about answering (ISC)2 questions successfully.
My questions may not be perfect. However this is about dissecting questions successfully.

[zackclay]

I was thinking the "environmental" was the environment of the network, business, etc. Only when you stated ideas about temperature did it cross my mind. Good question.

[kaileys]

I had to watch it twice as I was bit confused, I applied your exam tip 7 'People, Process, Technology', and picked 'a'

[hassanlodhi]

I was confused between A and C but chose C because I believed that whatever product you’re going to buy it should be able to address your needs above all.

[whiskeyrat]

I suppose C is in line with considering CIA(AA) in regards to confidentiality and accountability.

[m.henawy]

But being trustworthy would probably lead to C ?like if you go to gartner to check top vendors selling firewalls

[cyberabad]

I think environmental demands means infrastructure environment like network, O.S, and i was expecting answer should be b because if you dont have a good firewall rule set then that firewall is of no use..Like one bad rule is a hole in a firewall... So confusion between b and c..Packet examining will also be dependent on what rule we set..

[truthtriumphs]

How much does it cost training with you?

[kirank]

Option B - Firewall rule covers what kind of monitering/filtering and logging from option C. Environment is not literally climatic conditions it the nature of business.
Please analyse.