Agnolo Bronzino's painting of Eleonora di Toledo is categorized as fine art.

An example of a complex system in the U.S. is

a. Photosynthesis b. The chemical formula for Oxygen c. The U.S. Economy

In 1969, the Who produced ________, an album that is considered to be the first "rock opera."

Fill in the blank(s) with the appropriate word(s).