Final answer:
Option (c) The superiority of Android versus iPhone is a matter of personal preference would best conclude the essay by effectively summarizing its main idea.
Step-by-step explanation:
The best choice to conclude the essay and effectively summarize its main idea is option (c) The superiority of Android versus iPhone is a matter of personal preference. This option encapsulates the main argument of the essay that the debate between Android and iPhone revolves around personal preference and there is no definitive answer to which one is superior. It acknowledges that different individuals may have different preferences, and therefore, the conclusion implies that there is no one-size-fits-all answer to the debate.