The correct answer is D. They cannot afford them.
Explanation
The green revolution was a trend that began in the mid-twentieth century, this initiated in the United States and transferred to the rest of the world to increase agricultural productivity through the implementation of new technologies and techniques. However, these technologies are often expensive especially in comparison to traditional tools and technologies. As a result of this, the green revolution only affected positively to those that could afford new technology while regular peasants could not buy this and continue using traditional methods. According to this, peasants do not use the machinery and fertilizers of the green revolution because they cannot buy them due to their highs costs, this added to the fact that the peasants are not commonly wealthy. So, the correct answer is D. They cannot afford them.
