A nurse is assessing a client who is taking levothyroxine. The nurse should recognize that which of the following findings is a manifestation of levothyroxine overdose?

Choice A reason: Hypoactive deep-tendon reflexes are associated with hypothyroidism, not levothyroxine overdose. Overdose mimics hyperthyroidism, increasing metabolism and causing hyperactive reflexes due to heightened neural excitability, making this choice incorrect for overdose manifestations. Choice B reason: Drowsiness is linked to hypothyroidism or sedative effects, not levothyroxine overdose. Overdose causes hypermetabolic symptoms like agitation and insomnia due to excessive thyroid hormone stimulating the nervous system, making this choice incorrect. Choice C reason: Tachycardia is a manifestation of levothyroxine overdose, as excess thyroid hormone increases metabolic rate and stimulates beta-adrenergic receptors, elevating heart rate. This mimics hyperthyroidism, making it a key sign of overdose and the correct choice. Choice D reason: Hypothermia is associated with hypothyroidism, not levothyroxine overdose. Overdose causes hyperthermia due to increased metabolism and heat production from excessive thyroid hormone, making this choice incorrect for overdose symptoms.