Which of the following statements I - II - III and IV is definitely true in the context of the passage? I. There is every likelihood of survival of the human species as a consequence of nuclear war. II. Nuclear war risks and harmful eff ects are highly exaggerated. III. The post war survivors should be exposed to the benefits of non-lethal radiation. IV. Living organisms in the areas which are not directly aff ected by nuclear was would also suff er.