The levels of biodiversity include:

The correct answer is Option (3) → Ecological diversity, species diversity and genetic diversity

Option (1) Genetic diversity and species diversity — Incorrect. Genetic and species diversity are two of the levels, but this leaves out ecological diversity, the variety of ecosystems such as deserts, rain forests, mangroves and coral reefs.

Option (2) Species diversity and ecological diversity — Incorrect. Species and ecological diversity are two of the levels, but this leaves out genetic diversity, the variation within a species, such as the many strains of rice or the different potencies of Rauwolfia vomitoria.

Option (3) Ecological diversity, species diversity and genetic diversity — Correct. Biodiversity is studied at three levels: genetic diversity (within a species), species diversity (between species) and ecological diversity (between ecosystems).

Option (4) Ecological diversity, genetic diversity — Incorrect. Ecological and genetic diversity are two of the levels, but this leaves out species diversity, the variety of species in a region, as when the Western Ghats have more amphibian species than the Eastern Ghats.

NCERT Extract:
Biodiversity – “Biodiversity is the term popularised by the sociobiologist Edward Wilson to describe the combined diversity at all the levels of biological organisation. The most important of them are– (i) Genetic diversity : A single species might show high diversity at the genetic level over its distributional range.”