(b) hyposecretion of adrenal gland

Explanation:

Addisons disease occurs due to hyposecretion of both mineralocorticoids (aldosterone) and glucocorticoids (cortisol) from the layers of adrenal cortex called zona glomerulosa and zona fasciculata respectively. The disease is characterized by excessive loss of Na⁺, Cl^– and HCO₃ increased K⁺ level in blood, weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and nonexposed parts of the body.