So the question ask who among the following has a transcendentalist belief that saying Whoso is a man must be a nonconformist and the answer would be letter A. Ralph Waldo Emerson. I hope you are satisfied with my answer and feel free to ask for more
Explanation: according to this passage the reason of the failure of League of Nations was attitude of the USA: USA did not join which undermined prestige, reputation and effectivity of the League.