questions about Call of Duty 4

I'm sitting here on a really difficult Call of Duty quiz and I have one question which I cannot answer:

Which new feature makes the fights in CoD4: Modern Warfare more dangerous?
A: You have to watch out for radioactive radiation
B: The dogs of your enemies can smell your position even when you are perfectly camouflaged
C: A lot of bullets strike through fences and thin walls

Probably someone may help me out :thumbsup:

Thanks

 

Shooting through walls definitely.

 

C, becuase the radiation thing is for a couple of levels only.

 

Yeah I agree with C

 

thanks guys. I hope I will win something.