Concept:Ozone depletion is the environmental hazard caused mainly by human activities.Explanation:Hurricanes, earthquakes, and volcanic eruptions are natural environmental hazards.Human activities release chlorofluorocarbons (CFCs) and other ozone-depleting substances into the atmosphere.These substances destroy the ozone layer, leading to ozone depletion.Therefore, ozone depletion is due primarily to human activities.Answer:B. ozone depletion