Assertion : Threatened species are those living species which have been greatly reduced in their number and are liable to become extinct if the causative factors continue.
Reason : IUCN is an international organisation which maintains the IUCN red list of threatened species, to assess the conservation status of different species.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.