Endangered species are those that

(a) are harmful to humans

(b) have a very low population and risk extinction

(c) are newly discovered 

(d) are domesticated

Correct answer: (b) Have a very low population and risk extinction

Endangered species are those whose numbers have fallen so low—or are declining so rapidly—that they face a high risk of extinction in the near future. This status is based on scientific criteria such as sharp population decline, very small or fragmented populations, severely restricted range, and ongoing threats (habitat loss, poaching, invasive species, pollution, climate change).

• High extinction risk: Endangered is a formal threat category used by national Red Data Books and the IUCN Red List (e.g., “Endangered”, “Critically Endangered”).
• Causes: Habitat destruction/fragmentation, overexploitation, illegal wildlife trade, human–wildlife conflict, diseases, and climate-driven changes.
• Examples: In India—Asiatic lion (Gir landscape), Great Indian bustard, Gangetic river dolphin; globally—Sumatran orangutan, Hawksbill sea turtle.
• Conservation actions: Protected areas, species recovery programs, anti-poaching, habitat restoration, community-based conservation, and legal protection.

Why the other options are incorrect

• (a) Are harmful to humans – A species’ danger to humans has nothing to do with its conservation status.
• (c) Are newly discovered – New discovery doesn’t imply endangerment; status depends on population trends and threats.
• (d) Are domesticated – Domesticated species (e.g., cattle, dogs) are not classified as endangered in the wild context.

Final answer: (b) Have a very low population and risk extinction.