Which of the following hierarchies is correct with reference to the levels of biological organization?

The genus $Quercus$ is a dominant component in:

$A$ regulators are able to maintain homeostasis by means which ensure constant body temperature,constant osmotic concentration,etc. All $B$ and $C$ and a very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation).
Evolutionary biologists believe that the 'success' of mammals is largely due to their ability to maintain a constant body $D$ and thrive whether they live in Antarctica or in the Sahara desert.
Choose the correct option for $A, B, C$ and $D$.

Warm-blooded animals like mammals from colder climates generally have shorter ears and limbs. This is an explanation of:

The treeless biome of cold climates is:

In a sea shore,the benthic animals live in sandy,muddy and rocky substrata and accordingly developed the following adaptations:
$(a)$ Burrowing
$(b)$ Building tubes
$(c)$ Holdfasts / peduncle
Match the suitable substratum against each adaptation.