A 51-year-old woman is diagnosed with primary osteoarthritis (OA) of the knee. The NP will educate the woman that which of the following could have contributed to or might worsen her OA?

Choice A reason: Diabetes mellitus is a metabolic disorder and is not a primary contributor to OA; congenital abnormalities alone are less commonly a major factor. Choice B reason: While overuse and obesity contribute to OA, diabetes mellitus is not considered a key causal factor. Choice C reason: OA risk increases with mechanical stress on joints, cumulative overuse, obesity that increases joint load, and aging-related degeneration of cartilage, making this the most accurate combination of contributing factors. Choice D reason: Congenital abnormalities can predispose to OA in some cases, but aging is a far more common contributing factor overall.