Concept:Habitat loss is the most serious threat to biodiversity and pushes many species toward extinction.
Explanation:All species rely on their natural habitats for food, shelter, and breeding.
When these habitats are destroyed or broken apart, animal and plant populations fall sharply.
Because so many species are affected by this loss, disappearing habitats are considered the main cause of endangerment.
Rising temperatures, acid rain, and hazardous wastes also threaten wildlife, but they impact fewer species than habitat destruction does.
Answer:A. disappearing habitats