OE by Kaplan
The semicolon indicates that the second part of the sentence defines the blank. Since the demonstration lacked organization and actually hurt the activists’ cause, a good prediction for the blank would be “disaster.” Choices (B) debacle and (D) fiasco both mean “disaster,” and are therefore correct.

Choices (A) stalemate and (C) impasse are synonyms, which make them attractive, but both mean “deadlock.”“Deadlock” suggests a lack of production, but not counter-productivity, so these choices are incorrect. Choice (E) obstacle means “roadblock,” and (F) enigma means “mystery.” Neither matches our prediction, nor do any of the other answer choices have a meaning similar to either of them, so both are incorrect.

Choices (B) and (D) are the correct answers.