Why are coral reefs not found in the regions from west Bengal to Andhra Pradesh but are found in Tamil Nadu and on the east coast of India ?

$A$... regulators are able to maintain homeostasis by means which ensures constant body temperature, constant osmotic concentration, etc. All ...$B$... and ...$C$.... and is 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 $D$

$A$ : Antarctic fishes have blubber to withstand sub zero temperatures.
$R$ : Blubber are proteins which allow the freezing of body fluids.

Assertion : Animals adopt different strategies to survive in hostile environment.

Reason : Praying mantis is green in colour which merges with plant foliage.

The salinity in sea water in parts per thousand $(ppt)$ ranges between