The IUCN Red List is a catalogue of –

The correct option is Species threatened with risk of extinction.

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, established in 1964, is the world's most comprehensive information source on the global conservation status of animal, fungus, and plant species.

It acts as a critical indicator of the health of the world's biodiversity. By assessing the extinction risk of tens of thousands of species, the Red List guides conservation actions and policy decisions to help save the species facing the highest risks of extinction.