The correct answer is option (3), because the flippers of the Penguins and Dolphins perform similar function but they are not anatomically similar structures. This is example of analogous structures. • Option (1) is incorrect as adaptive radiation is the process of evolution of different species in a given geographical area starting from a point and literally radiating to the other areas of geography. • Option (2) is incorrect as natural selection is a key mechanism of evolution. • Option (4) is incorrect as divergent evolution results in the formation of homologous structures.