Define it, or use a more familiar word.
D. The independent clause is after a "," and does not rely on the sentence.
Based on that passage, I'd say the young man is active because he's jogging, and friendly he smiled in encouragement to elderly men. Nothing in the passage indicates that he is either intelligent or snobbish.
The writers probably used WW2 to base the human rights on so that it would be based on major problems that needed token care of.