The sentence addresses the dynamics within decision-making processes, particularly within organizational or governing bodies, when the pursuit of unanimity or complete agreement becomes the primary objective. While "union" can refer to a state of togetherness or unity, it doesn't quite capture the idea of unanimity or complete agreement among members, which is the context in the sentence. "Unanimity" and “union” more accurately convey the idea of everyone being in agreement. "Downplay" means to minimize or make something appear less significant. In the sentence, the context suggests that dissenting voices are being suppressed or silenced, not merely minimized. "Stifled" and ‘muted’ effectively convey this idea of dissent being silenced or suppressed. "Obey" means to comply with or follow commands or orders. In the context of decision-making, it doesn't accurately convey the idea of decision-makers conforming to prevailing opinions due to pressure for unanimity. "Conform" and “adapt” better capture the idea of aligning with prevailing opinions or norms. Therefore, combinations of the words in 2 and 3 convey the idea accurately and thereby are correct answers. Hence, option D is the correct answer.