Answer:
c. fittest descent with modification
Step-by-step explanation:
Evolution can be defined, in a nutshell, as the process of variation and adaptation of populations over time, and may even cause the emergence of new species from a pre-existing one. In short, evolution is the process that gives rise to a fittest descent with modification. Thus, the great diversity of organisms present on our planet can be explained through this theory.
As we study evolution, we realize that the life forms we know today are not the same as those that lived thousands of years ago. This means that species have an evolutionary history and that many changes happen to them until there are the characteristics we observe today.
Species, therefore, are not fixed, have undergone changes throughout their history on the planet and continue to change. Man, for example, did not appear on earth as we see today, as there were several ancestral species.