In certain species of songbirds, development of the song requires the opportunity to hear the appropriate song during a sensitive period in life as well as the genes to prepare them to learn the song. This is a(n) ____ explanation of birdsong.

In certain species of songbirds, development of the song requires the opportunity to hear the appropriate song during a sensitive period in life as well as the genes to prepare them to learn the song. This is a(n) ____ explanation of birdsong.

a. physiological
b. ontogenetic
c. evolutionary
d. functional