What do mineralocorticoids primarily affect in the body?

Mineralocorticoids primarily affect electrolyte levels in the body, with a particular focus on sodium and potassium. The most well-known mineralocorticoid is aldosterone, which plays a crucial role in regulating the balance of electrolytes by promoting sodium reabsorption and potassium excretion in the kidneys. This action helps maintain appropriate fluid balance and blood volume. As a result, it indirectly influences blood pressure, but the primary mechanism of mineralocorticoids is directly linked to the control of electrolyte levels. Hence, the correct answer highlights the fundamental role that mineralocorticoids play in maintaining electrolyte homeostasis.