Which word means made tough by habitual exposure?

The term "inured" specifically refers to someone who has become accustomed to a particular condition, usually one that is unpleasant or challenging, through prolonged exposure. It carries the connotation of developing resilience or toughness as a result of repeated experience with difficult circumstances. For instance, an individual may become inured to harsh weather conditions after living in a cold climate for many years, meaning they have grown accustomed to it and do not find it as bothersome as they once did.

In contrast, the other choices do not convey the same meaning. "Poverty" refers to a state of being poor and does not imply any process of becoming tough. "Illusory" relates to something that is deceptive or misleading, which is not connected to the idea of developing resilience. "Fortuitous" refers to something happening by chance or luck, lacking any indication of habitual exposure or the toughness that results from it. Thus, "inured" is the term that best fits the definition of being made tough by habitual exposure.