Given the map of the average cotton yield around the world, which of the following statements can be inferred about the regions in which cotton is produced?

a. cotton grows well in regions that are densely populated
b. the region in which cotton originated remains the worlds primary producer of cotton
c. a countries level of development is more likely than climate to predict the location of cotton producers
d. cotton is a plant that is best grown in the semiarid regions of the world
e. africa is still the largest producer of cotton in the world