Which statement is correct about patient tolerance to medications?

Choice A reason: Tolerance reflects receptor desensitization or enzyme induction; higher doses compensate for reduced drug efficacy, a common pharmacological adaptation. Choice B reason: Organ failure affects metabolism, not tolerance; tolerance is a cellular response, not solely a failure of liver or kidney drug clearance mechanisms. Choice C reason: Stable dosing contradicts tolerance; if tolerance develops, efficacy drops, necessitating dose increases, not maintenance, to achieve therapeutic levels. Choice D reason: Non-adherence may alter response, but tolerance occurs with consistent use; it’s a physiological adaptation, not a result of misuse or skipping doses.