Edgar Guest is an American poet, famous for his optimistic tone. He was also called People's Poet.
A hero is defined as someone who is valuable or appreciated by his achievements or good qualities or by his courage.
In the third option, the speaker contrasts two different groups: first one is described in line 3 of the excerpt ("Are you one...?") and the characteristics of the other group are defined in the other lines (The things that...) and the final line adds emphasis by asking a direct question. The semantic field is also related in the statement and in the excerpt (uncharted, new discoveries, path and undone things, lead, way), making the third option the right answer.
the key to identify the tense in this sentence is 'have met' have is a helping verb here and met is the verb. met is the past tense of meet. hope this helps you. Fighting!