A 28-year-old woman presents to the emergency department with acute-onset right-sided hemiparesis and expressive aphasia that began 90 minutes ago. She denies recent trauma, fever, or headache preceding symptom onset. Past medical history includes migraine with visual aura occurring 2-3 times monthly. She has taken a combined oral contraceptive (ethinyl estradiol/levonorgestrel) for the past 3 years for contraception. Vital signs are within normal limits (BP 122/78 mmHg, HR 78/min, RR 14/min, temp 36.8°C, SpO2 99% on room air). Physical examination confirms acute left middle cerebral artery territory stroke on clinical testing. Brain MRI confirms acute ischemic stroke in the left MCA distribution. Serum glucose is 94 mg/dL. Electrocardiography and telemetry reveal normal sinus rhythm with no evidence of atrial fibrillation. Laboratory studies show total cholesterol 168 mg/dL, HDL 52 mg/dL, LDL 94 mg/dL, triglycerides 95 mg/dL. Thrombophilia workup is pending. Which of the following is the most significant modifiable risk factor contributing to her acute ischemic stroke in this clinical context?

1. A)Migraine with aura as an independent risk factor for ischemic stroke
2. B)Untreated hypertension based on current blood pressure readings
3. C)Combined oral contraceptive use in the setting of migraine with auraGABARITO
4. D)Hyperlipidemia evidenced by elevated LDL cholesterol
5. E)Underlying thrombophilia as the primary etiology of acute stroke