At what point is a government responsible for intervening in domestic and foreign
crises?

The correct answer is: A: One must know the process of hiring servants.

Explanation:

The central idea of this excerpt is expressed by option A: One must know the process of hiring servants. More specifically, the point being made is that prior to hiring servants, princes must test their loyalty and their ability to truly serve, because, according to the author, any servant who prioritizes his or her own interests or needs before the prince's is untrustworthy, and therefore an inadequate servant.