Which of the following regions is $NOT$ a biodiversity hotspot?

The Amazon rainforest is home to more than $...........$ species of invertebrates.

Where are the Cardamom Hills located?

Tropical regions show the greatest level of species richness because:
$A$. Tropical latitudes have remained relatively undisturbed for millions of years,hence more time was available for species diversification.
$B$. Tropical environments are more seasonal.
$C$. More solar energy is available in the tropics.
$D$. Constant environments promote niche specialization.
$E$. Tropical environments are constant and predictable.
Choose the correct answer from the options given below.

Describe biodiversity.

Define/Explain: $\gamma$-diversity.