The correct option is D
The different varieties of living organisms and ecosystems in a given area reflect the biodiversity. Biodiversity hotspots are areas with a high degree of species richness and endemism (species confined to that region and not found anywhere else) but facing a rapid rate of biodiversity loss. Species richness refers to the sum total of all the different species present in a particular geographical area.
The Indo-Gangetic Plain is the odd one out as it is not a biodiversity hotspot of India. It is a fertile stretch of land that covers most of northern and eastern India, parts of eastern Pakistan, almost all of Bangladesh and southern plains of Nepal.
It derives its name from the rivers flowing through these regions, i.e, Indus and Ganga. Although this belt houses several species of animals (elephants, antelopes, Asiatic lions and cheetahs), it is not considered as a hotspot as the degree of endemism is less.
India has 3 major biodiversity hotspots as follows :
- Western Ghats and Sri Lanka
Figure : Indo-Gangetic Plain