All of the sentences provided articulate a central idea, but if we are looking for the one that captures a broader theme likely applicable to various contexts, the sentence "Power, when placed in the wrong hands, can sometimes lead to corruption." is a strong example of a central idea. It encapsulates a universal truth about power dynamics and moral responsibility.
However, the other sentences also convey important themes and could be considered central ideas in their respective contexts, depending on the focus of a discussion or analysis. If there is a need to select only one, the sentence about power is likely the most universally applicable.