## **Core Concept**
Adrenal insufficiency, also known as Addison's disease, is a condition where the adrenal glands do not produce enough cortisol and/or aldosterone. The management of adrenal insufficiency involves replacing these deficient hormones.

## **Why the Correct Answer is Right**
The drug of choice (DOC) in adrenal insufficiency is **Fludrocortisone** along with **Hydrocortisone**. However, among the given options, **Hydrocortisone** is a primary glucocorticoid replacement. Fludrocortisone is a mineralocorticoid used for aldosterone replacement. Hydrocortisone is used because it has both glucocorticoid and some mineralocorticoid activity, making it suitable for replacement therapy in adrenal insufficiency.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Not specified, assuming incorrect based on standard treatment protocols.
- **Option B:** Not specified, assuming incorrect based on standard treatment protocols.
- **Option D:** Not specified, assuming incorrect based on standard treatment protocols.

## **Clinical Pearl / High-Yield Fact**
In patients with adrenal insufficiency, it's crucial to administer **Hydrocortisone** (a glucocorticoid) and **Fludrocortisone** (a mineralocorticoid) to replace the deficient hormones. During acute illness or stress, the dose of **Hydrocortisone** should be increased to prevent adrenal crisis.

## **Correct Answer:** . Hydrocortisone