The fact that people sometimes kill others, pollute the environment, and abuse their own bodies is most difficult for which theory of personality to explain

Humanistic theory

Explanation:

According to humanistic psychologists, the practice of free will is  the basic existential assumption.  Personal agency relates to the decisions that we make in life, the paths that we go down, and their impact. The strategy is positive and reflects on the virtuous potential of humanity to conquer suffering, pain, and desperation. The psychodynamic theory was also opposed by humanist psychology as it is often deterministic, with implicit irrational and instinctive factors influencing individual thoughts and actions.

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.

world bank is the correct answer.