Just wanted to point out that this is a GRE question, and a question based on the old GRE format to boot. That said, let's take apart this two-blank sentence completion.
For the first blank we want to look at the words, 'mastery in miniature,' and a 'world that seems...' These words lead to the interpretation: People strive to control a world that seems uncontrollable. Therefore for the first blank we want a word that is the noun form of uncontrollable. 'Chaos' works well.
There is a contrast with the second part of the sentence, which follows the comma (the word 'while' indicates this). The contrast is that some see the practical joke not as a form of controlling the uncontrollable (first part of the sentence) but of reducing everything to the opposite: chaos.
Essentially, the words in the two blanks are synonyms.
Only (D) has two words that are synonyms and mean chaos (indeed that is the word for the second blank). (C) has harmonious, which is the opposite of what we want.
Hope that helps
Magoosh Test Prep