## **Core Concept**
The question describes a female child presenting with virilization, hypertension, and low plasma renin activity. This combination of symptoms suggests an underlying condition related to excessive production of androgens and mineralocorticoids. The key to solving this question lies in understanding the relationship between these symptoms and specific disorders of adrenal gland function.

## **Why the Correct Answer is Right**
The correct answer, **Congenital Adrenal Hyperplasia (CAH) due to 11-beta hydroxylase deficiency**, explains all the symptoms presented. This condition leads to an overproduction of androgens, causing virilization in female children, and an overproduction of deoxycorticosterone (DOC), a potent mineralocorticoid, leading to hypertension. The hypertension is associated with low plasma renin activity because the excessive mineralocorticoid activity (from DOC) causes volume expansion and sodium retention, suppressing the renin-angiotensin-aldosterone system.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While **Cushing's syndrome** can cause hypertension and virilization due to excess cortisol (which has mineralocorticoid and androgenic effects at high levels), it typically does not present with low plasma renin activity as a defining feature; instead, it often causes hypokalemia and hypertension with low renin, but the constellation of findings and the specific enzymatic deficiency points more towards CAH.
- **Option B:** **Androgen-secreting tumors** can cause virilization but are less commonly associated with hypertension and low renin activity in a straightforward manner without other systemic symptoms.
- **Option D:** **17-alpha hydroxylase deficiency**, another form of CAH, typically presents with hypertension and hypokalemia due to excessive mineralocorticoid production but is associated with sexual infantilism (due to decreased androgen and estrogen production) rather than virilization.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is to remember that Congenital Adrenal Hyperplasia due to **11-beta hydroxylase deficiency** is a common cause of hypertension in children and is associated with virilization in females, low renin activity, and elevated levels of 11-deoxycorticosterone (DOC). This condition is a classic cause of secondary hypertension in pediatric patients.

## **Correct Answer:** . 11-beta hydroxylase deficiency.