Harte's vivid description of the outcasts' travels creatures a sense of

a) bright optimism
b) impending doom
c) happy camaraderie
d) suspenseful mystery

this answer to this question is c. allegory

why?

stories with allegories have a hidden symbolic meaning with a theme. the hidden meaning can be political, or other real life problems.

the statement that identifies the central idea of "the salem and other witch trail hunts" is d. while witch hunts may feel like a rare occurrence, mike kubic proves that such   incidents are not as uncommon as we originally thought.

the author is trying to show that witch hunts come in various forms and are produced by the fear of what isn't understood or it's different.