In malignant hypertension, hallmark is -a) Fibrinoid necrosisb) Hyperplastic arteriolesc) Hyalinizationd) All of the above

**Core Concept**
Malignant hypertension is a severe form of high blood pressure that can cause damage to organs such as the kidneys, heart, and eyes. The underlying principle being tested is the pathological changes that occur in the blood vessels due to extremely high blood pressure.

**Why the Correct Answer is Right**
The correct answer, **Fibrinoid necrosis**, is a characteristic feature of malignant hypertension. It refers to the deposition of fibrin and other proteins in the arterial walls, leading to necrosis of the vessel wall. This is a result of the severe vascular injury caused by the high blood pressure.

**Why Each Wrong Option is Incorrect**
**Option B:** Hyperplastic arterioles are a feature of benign hypertension, not malignant hypertension. **Option C:** Hyalinization is a feature of benign hypertension, where there is thickening of the arterial walls due to the deposition of hyaline material. **Option D:** is incorrect because not all of the above options are correct.

**Clinical Pearl / High-Yield Fact**
Malignant hypertension is a medical emergency that requires immediate attention. The presence of fibrinoid necrosis is a hallmark of this condition and can be seen on histopathological examination of affected organs.

**Correct Answer:** a) Fibrinoid necrosis