What does '$W$' represent in the given figure?

Match the columns:

Column-$I$	Column-$II$
$(i)$ Nile perch in Lake Victoria	$(i)$ Obvious reasons for habitat destruction
$(ii)$ Narrowly utilitarian	$(ii)$ Habitat destruction
$(iii)$ Main cause for biodiversity loss	$(iii)$ High endemism
$(iv)$ Hotspot	$(iv)$ Alien species

$A$: Western Ghats are included among the hot spots of biodiversity.
$R$: Western Ghats have greater amphibian diversity than Eastern Ghats.

Which of the following pairs of an animal and a plant represents endangered organisms in India?

In the given pie chart,what do '$a$' and '$b$' represent respectively?

Identify the incorrect statement.
$I$. Speciation is generally a function of time.
$II$. Tropical environment is less seasonal,relatively more constant and predictable.
$III$. Solar energy contributes to high productivity.
$IV$. Temperate regions have remained relatively undisturbed for millions of years.