Which of the following developments occurred first?
a. cash crops
b. animal domestication
c. the industrial revolution
d. the green revolution

The correct answer is B. Animals were first domesticated around 15,000 years ago, beginning with the wolf into a dog. Other early animals to be domesticated were cats, sheep, pigs, and goats. Cash crops were first introduced in the 1600's, the Industrial revolution occurred in the 1760's, and the green revolution occurred between the 1930's and 1960's.