Tropical regions account for greater biological diversity because of the following reasons, except:

Lower predation due to diversity of food availability

The correct answer is Option (2) → Lower predation due to diversity of food availability 

Lower predation due to diversity of food availability :Incorrect. Predation in tropical regions is not necessarily lower. In fact, predators often play a crucial role in maintaining diversity through natural selection and regulating populations. The diversity of food availability contributes to biodiversity, but it does not reduce predation.

Ecologists and evolutionary biologists have proposed various hypotheses; some important ones are:

•  Speciation is generally a function of time, unlike temperate regions subjected to frequent glaciations in the past, tropical latitudes have remained relatively undisturbed for millions of years and thus, had a long evolutionary time for species diversification,
•  Tropical environments, unlike temperate ones, are less seasonal, relatively more constant and predictable. Such constant environments promote niche specialisation and lead to a greater species diversity.
•  There is more solar energy available in the tropics, which contributes to higher productivity; this in turn might contribute indirectly to greater diversity.