What does '$X$' represent in the given graph?

$A$ species facing an extremely high risk of extinction in the immediate future is called:

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

Match the columns:

Column-$I$	Column-$II$
$(A)$ Endemism	$(i)$ Khasi and Jaintia hills,Meghalaya
$(B)$ Hotspot of India	$(ii)$ Advanced ex-situ conservation
$(C)$ Sacred groves	$(iii)$ Species found in a particular area only
$(D)$ Cryopreservation	$(iv)$ Zoological park and botanical garden
$(E)$ Ex-situ conservation	$(v)$ Western Ghats

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.

Given below are two statements.
Statement $I$: $Rauwolfia$ $vomitoria$ found in Himalayan ranges shows variation in potency and concentration of active component reserpine.
Statement $II$: Ecosystem diversity is observed in regions of Rann of Kutch.
In the light of the above statements,choose the correct option.