Whitman and Heinroth Each, Independently, Suggested That Some Patterns of Movement

Multiple Choice

Whitman and Heinroth each, independently, suggested that some patterns of movement might be just as reliable as morphological characters in defining particular species of birds. This is because

A) each individual bird is a unique combination of hereditary and environmental influences.
B) the displays of all species are often exceptionally similar to one another.
C) the displays within different species are often exceptionally constant.
D) the displays within a species are often quite variable from individual to individual.