There are the most clues for the word in the second blank, so start there. The clue is “wariness of human motives.” Of the choices, the word closest in meaning to this is cynicism. Now, use cynicism to determine the word in the first blank. The trigger “though” indicates that the writer explores more than just cynicism; thus, he is not a cynic. Of the choices, the word closest in meaning to cynic is misanthrope. Finally, “though” also clues us in to the meaning of the last word. It should characterize behavior that contrasts with what a cynic would expect. A simple word here is“good.” Of the choices, the word closest in meaning to good is benevolence.