What is the process of metamorphosis?

Metamorphosis is specifically defined as the transformation of an animal from an immature form to an adult form, including distinct changes in structure, function, and often habitat. This process is most commonly associated with certain animal groups, including insects, amphibians, and some fish. During metamorphosis, there are significant morphological changes that occur; for example, a tadpole undergoes metamorphosis to become a frog, which involves changes not only in shape and size but also in the respiratory system, diet, and behavior.

In the context of this definition, it is clear that the other options do not accurately capture the essence of metamorphosis. While reproduction in amphibians and changes associated with aging or color adaptation may involve various biological processes, they do not encompass the transformative nature of metamorphosis as it relates to the developmental stages of certain animals.