The reason of large-scale diversity among the organisms is

Correct answer: (a) Adaptation

Explanation

The answer is adaptation. Over many generations, organisms adapt to very different habitats and ways of life, and natural selection keeps the forms that suit each one. This is the reason for the great diversity among organisms.

Mutation – a change in the base sequence of a gene – gives new heritable variation, the raw material on which adaptation works. In Neo-Darwinism, small genetic changes add up over generations through natural selection and adaptation, so new forms arise and diversity grows.

Polyploidy is only one special kind of genetic change, and cooperation does not explain diversity.