Option (D) is correct because threatened species are those which are suffering from the danger of extinction. Giant Panda, Leatherback turtles and Pacific walrus are some of the examples of threatened species who are facing the danger of extinction.

Option (A) is not correct because lions and tigers are not threatened species. They are endangered species.

Option (B) is not correct because threatened species are not abundant in number but their number is increasing day by day.

Option (C) is not correct because threatened species does not mean that it threats other. Threatened species does not harm or do something unpleasant.