The "Red Data Books" published by the International Union for Conservation of Nature and Natural Resources (IUCN) contain lists of 1. Endemic plant and animal species present in the biodiversity hotspots. 2. Threatened plant and animal species. 3. Protected sites for conservation of nature and natural resources in various countries. Select the correct answer using the codes given below :

1. The IUCN Red List of Threatened Species, often referred to in the context of 'Red Data Books', is the world's most comprehensive inventory of the global conservation status of biological species. 2. Statement 1 is incorrect: While many endemic plant and animal species in biodiversity hotspots might be threatened and thus listed, the Red List itself is not primarily a list of endemic species or species exclusive to hotspots. Its focus is on threat status. 3. Statement 2 is correct: The core purpose of the IUCN Red List is to evaluate the extinction risk of thousands of species and subspecies. It specifically contains lists of threatened plant and animal species, categorizing them based on criteria (e.g., Critically Endangered, Endangered, Vulnerable). 4. Statement 3 is incorrect: The IUCN Red List focuses on the status of species, not on protected sites. Information on protected sites is maintained in other databases, such as the World Database on Protected Areas (WDPA), which is managed by UNEP-WCMC in collaboration with IUCN. Therefore, only statement 2 accurately describes the content of the IUCN Red List/Red Data Books.