Why is generic diversity important for survival of populations

Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population.  Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.

Explanation:

the answer is d. made landless peasants that owners of large haciendas

b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.