What is the role of the kidneys in the body's electrolyte balance?

The correct answer highlights the kidneys' vital function in maintaining the body's electrolyte balance, specifically through the regulation of sodium, potassium, and calcium levels in the blood. The kidneys play a key role in homeostasis, which is the body's ability to maintain stable internal conditions.

By selectively reabsorbing or excreting these electrolytes in response to the body's needs, the kidneys help to ensure that the concentrations of these ions remain within a healthy range. For instance, when sodium intake is high, the kidneys can increase sodium excretion to balance the levels; similarly, they can adjust potassium and calcium levels based on dietary intake and other physiological signals.

In contrast, the other options do not accurately reflect the primary role of the kidneys in electrolyte management. While vitamins and glucose are important in the body, the kidneys are not primarily responsible for their production or management in the way that they control electrolyte levels. Additionally, although detoxification is a function of the kidneys, it is not exclusive to their role, nor does it pertain to managing electrolyte balance specifically. Thus, the correct answer emphasizes their central role in regulating essential electrolytes, which is crucial for maintaining overall health.