Step 1: Understanding the Concept
Biodiversity is studied at three linked levels.
Step 2: The levels
Genetic diversity is the variation of genes within a species, i.e. intraspecific diversity. Species diversity is the variety of species in a region, i.e. interspecific diversity. Ecological diversity is the variety of habitats, communities and ecosystems.
Step 3: Conclusion
So the three levels are intraspecific, interspecific and ecological diversity.
Final Answer:
The three levels are interspecific, intraspecific and ecological diversity.
\[ \boxed{\text{(C) }\text{interspecific, intraspecific and ecological}} \]