Which of the following factors is the most important factor for the loss of biodiversity?

1. A

   Genetic assimilation

   Option (a) claims genetic assimilation causes biodiversity loss. While it is a real ecological concern, it is not the primary driver of global species decline.

2. B

   Control of predators

   Option (b) points to the control of predators. This affects trophic cascades and ecosystem balance, but habitat loss remains a far more massive threat.

3. C

   Destruction of natural habitat

   Option (c) states that destruction of natural habitat is the most important factor for the loss of biodiversity. Deforestation, urbanization, and land-use change directly eradicate the living spaces, food sources, and breeding grounds of countless species, making it universally recognized by ecologists as the leading cause of extinction today.

4. D

   Pest control

   Option (d) highlights pest control. Chemical pesticides and localized pest management certainly damage non-target species and pollinators, yet they operate on a smaller scale than complete habitat conversion.

Summary. Official key is (c) because habitat destruction directly removes the foundational ecosystems required for species survival. While genetic assimilation, predator control, and pest management create severe ecological pressures, none match the sheer scale of direct land transformation. Rapid urbanization and deforestation fragment populations beyond recovery. Consequently, environmental scientists consistently identify habitat loss as the primary threat to global biodiversity.