A. Correct option: B 
B. Explanation for correct option:

• The Western Ghats is one of hottest biodiversity spots.
• It occurs along western coast of India in Maharashtra, Karnataka, Tamil Nadu and Kerala.
• There is a high degree of species richness and endemism of flowering, non-flowering plants, reptiles, amphibians, insects, birds, fishes species.
• Many of species are undiscovered and many of m threaten species that occur in Western Ghats.
  
  

C. Explanation for incorrect option:

Option A: The large-scale planting of Bt cotton can influence natural crop. It can also increase risk of new insect varieties.
Option C: Developing countries are also involved in  biodiversity conservation e.g. India
Option D: Different animals are found in se desert areas but very few of m are rare animals.