Answer:
The correct answer is option D, a decrease in the cost to farmers who rely on mono cultures.
Explanation:
All the options except D, are the disadvantages of monoculture in the following ways
A) increased herbicide and pesticide use – Due to monoculture the nutrients in the soil gets depleted and thus more and more fertilizers are used which attracts more and more pests and to kill the pests more and more herbicides and pesticides are used
B) monoculture quickly depletes the soil of nutrients. – This is so because same crop uses same nutrient and continuous monoculture do not give land sufficient time to replenish its lost nutrients.
C) a decrease the genetic variation of certain gene pools – due to monoculture , probability of cross fertilization becomes nill
D) a decrease in the cost to farmers who rely on monocultures-there is no decrease in cost to farmers as input of fertilizer, herbicides and pesticides increases which enhances the cost.