The term "sixth mass extinction/sixth extinction" is often mentioned in the news in the context of the discussion of:

The correct answer is D. The phrase 'sixth mass extinction' refers to the current, human-driven loss of species, which scientists link to overexploitation of resources, habitat fragmentation and destruction, pollution and climate change. Earlier mass extinctions had natural triggers acting over long periods. The present rate of loss is far faster and is driven by a single species, which is why the Anthropocene framing is used.

Why the others fail:

• A describes a land-use problem, a real concern for native ecosystems, but it is one driver, not the global concept of a mass extinction.
• B is wrong because the sixth extinction is not about a meteorite. The event 65 million years ago was an impact, while the current debate is about anthropogenic causes.
• C confines the issue to GM crops and food biodiversity. Crop diversity matters, but it is a narrow slice of the wider picture.

Core concept: the sixth mass extinction is a biodiversity crisis. It connects to the Biological Diversity Act 2002, the IUCN Red List, and the Kunming-Montreal Global Biodiversity Framework adopted in December 2022, which set the 30 by 30 target of protecting 30% of land and sea by 2030. For Mains GS-III, link it to the climate-biodiversity nexus and the trade-off between development and conservation.

Trap: candidates pick A or C because they sound like specific, technical agricultural issues. The question asks for the broad, global phenomenon, and that is D.