Answer: The character that best represents a tragic hero is the one included in option D: "A vain king who values appearance over truth loses his throne and eventually his life after he tries to test the population's loyalty to him".
Explanation: A tragic hero is the main character of a tragedy. Although he has power at the beginning, he goes through a reversal of fortune and ends up facing his own downfall. A tragic hero always has a tragic flaw, such as pride, that leads him to his downfall. Option D. presents a hero "who values appearance over truth"; therefore, this can be considered his tragic flaw. Moreover, he experiences a reversal of fortune since he goes from being a powerful man, a king, from losing his throne and his life, that is to say he ends up experiencing a downfall.