Threatened species are any species (including animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment

Threatened species does not include extinct species. Let's understand this in detail.

Threatened Species
Threatened species are those that are at risk of becoming endangered or extinct due to various reasons such as habitat loss, climate change, hunting, poaching, pollution, etc. The International Union for Conservation of Nature (IUCN) has categorized threatened species into three categories - vulnerable, endangered, and critically endangered.

Categories of Threatened Species
1. Vulnerable species - These species are likely to become endangered if their population continues to decline.
Example: African elephant, cheetah, giraffe, etc.

2. Endangered species - These species are at a high risk of becoming extinct in the near future if their population continues to decline.
Example: Bengal tiger, giant panda, snow leopard, etc.

3. Critically endangered species - These species are at an extremely high risk of becoming extinct in the near future.
Example: Amur leopard, Javan rhinoceros, vaquita porpoise, etc.

Rare Species
Rare species refer to those species that have a very small population size and a limited geographic range. However, being rare does not necessarily mean being threatened. Some rare species may have a small population size due to their unique habitat requirements or low reproductive rate.
Example: Okapi, Komodo dragon, fossa, etc.

Extinct Species
Extinct species are those that no longer exist on Earth. These species have been completely wiped out due to natural or human-related causes such as habitat destruction, overhunting, climate change, etc.
Example: Dodo, Tasmanian tiger, passenger pigeon, etc.

Conclusion
From the above explanation, it is clear that threatened species do not include extinct species. Threatened species are those that are at risk of becoming endangered or extinct in the near future, whereas extinct species no longer exist on Earth.

Option 'd' cause threathened means endangered and the animals whose population has been almost eradicated