What is the most significant cause driving animals and plants to exti…

The correct answer is Option (3) → Habitat loss and fragmentation

The book names four major causes of biodiversity loss, together called “The Evil Quartet”: (i) habitat loss and fragmentation, (ii) over-exploitation, (iii) alien species invasions and (iv) co-extinctions. Of these, habitat loss and fragmentation is the most important cause driving plants and animals to extinction. When a forest is cleared or broken into small patches, the species that live there lose their homes.

Over-exploitation is one of the four causes, but not the main one. Pollution and natural disasters are not among the four causes listed in the book.

NCERT Extract:
Loss of Biodiversity – “… Causes of biodiversity losses: The accelerated rates of species extinctions that the world is facing now are largely due to human activities. There are four major causes (‘ The Evil Quartet ’ is the sobriquet used to describe them). (i) Habitat loss and fragmentation: This is the most important cause driving animals and plants to extinction. The most dramatic examples of habitat loss come from tropical rain forests. Once covering more than 14 per cent of the earth’s land surface, these rain forests now cover no more than 6 per cent.”