**Core Concept:** Cerebrovascular accidents (CVAs), also known as strokes, are a group of disorders characterized by sudden loss of brain function due to disruption of blood flow to the brain. The most common cause of CVA is a blockage in the cerebral arteries, which results in an Ischemic Stroke.

**Why the Correct Answer is Right:** Ischemic strokes account for approximately 80% of all strokes and are caused by the obstruction of a cerebral artery, typically due to a blood clot or plaque buildup. The correct answer, Ischemic Stroke (A), is caused by the blockage of cerebral arteries, leading to reduced blood flow and oxygen supply to the brain.

**Why Each Wrong Option is Incorrect:**

A. Hemorrhagic Stroke (B) is caused by bleeding into the brain, typically due to rupture of a blood vessel or aneurysm. This is not the correct answer as it refers to a different type of stroke.

C. Transient Ischemic Attack (C) is a temporary episode of neurological dysfunction caused by reduced blood flow in the brain, typically lasting less than 24 hours. Unlike an ischemic stroke, a TIA does not result in permanent brain damage. This is not the correct answer as TIA is a precursor to a stroke but is not the primary cause of stroke.

D. Cerebral Infarction (D) refers to a localized area of brain tissue death due to loss of blood supply. Although this is related to stroke, it does not specifically address the most common cause, which is an Ischemic Stroke.

**Clinical Pearl:** Early identification and management of risk factors for stroke, such as hypertension, smoking, and diabetes, can significantly reduce the risk of developing an ischemic stroke. Prompt medical intervention in cases of stroke symptoms can also improve the patient's prognosis and outcome.