'The Evil Quartet' of biodiversity loss is -

The correct answer is Option (3) → Alien species invasion, co-extinctions, habitat loss and fragmentation, over-exploitation

Option (1) Alien species invasion, co-extinctions, over-exploitation, sacred groves — Incorrect. Sacred groves protect biodiversity; they are a form of in situ conservation.

Option (2) Habitat loss and fragmentation, over-exploitation, sacred groves, mutualism — Incorrect. Sacred groves and mutualism, an interaction in which both species gain, do not cause loss.

Option (3) Alien species invasion, co-extinctions, habitat loss and fragmentation, over-exploitation — Correct. The four major causes of biodiversity loss, called ‘The Evil Quartet’, are habitat loss and fragmentation, over-exploitation, alien species invasions and co-extinctions.

Option (4) Alien species invasion, endemism, habitat loss and fragmentation, over-exploitation — Incorrect. Endemism means a species is found only in one region; it is a reason to protect an area, not a cause of loss.

NCERT Extract:
Loss of Biodiversity – “In general, loss of biodiversity in a region may lead to (a) decline in plant production, (b) lowered resistance to environmental perturbations such as drought and (c) increased variability in certain ecosystem processes such as plant productivity, water use, and pest and disease cycles. 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).”