The Larvae of Some Insects Are Merely Small Versions of the Adult

Multiple Choice

The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following most directly favours the evolution of the latter, more radical, kind of metamorphosis?

A) natural selection of sexually immature forms of insects
B) changes in the homeobox genes governing early development
C) the evolution of meiosis
D) the development of an oxidizing atmosphere on Earth
E) the origin of a brain