What common characteristic can be ascribed to the key cash crops of the period 1450-1750, sugar, tobacco and coffee?

a. They require temperate climate to grow
b. Europeans indentured servants performed the labor involved in their cultivation
c. Revenues from the sale of these goods did not cover the costs of production and transportation
d. Chinese demand for all three drove expansion of these crops
e. Each one has addictive qualities

Answer: e. Each one has addictive qualities