Many Closely Related Duck Species Exhibit ____, the Dramatic Variation

Multiple Choice

Many closely related duck species exhibit ____, the dramatic variation in the appearance of males but not females, which is an almost certain sign of ____.

A) asexual reproduction; sexual selection
B) asexual reproduction; artificial selection
C) sexual dimorphism; sexual selection
D) sexual dimorphism; artificial selection
E) sexual uniformitarianism; sexual selection