A 45-year-old man with a 10-year history of hypertension, diet-controlled, presents to the emergency department with acute onset right-sided weakness and right facial droop. Examination demonstrates dysarthria and a right pronator drift. Vital signs are BP 158/94 mmHg, HR 82, RR 14, temperature 37.2°C, SpO2 99% on room air. Cardiorespiratory examination is unremarkable with no murmurs or arrhythmias. Diffusion-weighted imaging (DWI) shows a 4 mm acute ischemic lesion in the left putamen. Subsequent laboratory workup includes a negative hypercoagulability panel, normal lipid profile (total cholesterol 160 mg/dL), normal HbA1c, normal ECG, and transthoracic echocardiography with normal ejection fraction and no evidence of thrombus or vegetation. Carotid ultrasound shows minimal atherosclerosis (<30% stenosis). Which of the following is the most likely classification of this stroke?

1. A)Cardioembolic stroke secondary to atrial fibrillation
2. B)Stroke of undetermined etiology
3. C)Large artery atherosclerotic stroke
4. D)Lacunar stroke secondary to chronic hypertensionGABARITO
5. E)Arterial dissection of the middle cerebral artery