**Core Concept**
Stroke-like presentations can be caused by hypertensive encephalopathy, especially in the absence of hemorrhage on imaging. This condition is characterized by high blood pressure leading to cerebral edema and potentially seizures or altered mental status.

**Why the Correct Answer is Right**
In the presence of high blood pressure (160/100 mmHg) and no evidence of hemorrhage on non-contrast computed tomography (NCCT), the most likely diagnosis is hypertensive encephalopathy. This condition requires immediate attention to lower the blood pressure to prevent further cerebral damage. The goal is to reduce the blood pressure by 20-25% within the first hour, while ensuring that the cerebral perfusion pressure is maintained to prevent ischemia. This can be achieved using intravenous antihypertensive agents such as nicardipine, clevidipine, or labetalol.

**Why Each Wrong Option is Incorrect**
**Option A:** Administering aspirin without addressing the blood pressure would not be appropriate, as it may increase the risk of bleeding in the setting of cerebral edema.
**Option B:** Performing a lumbar puncture in the setting of suspected hypertensive encephalopathy could exacerbate the condition and lead to transtentorial herniation.
**Option C:** Continuing to monitor the patient without taking any action would be inappropriate, as the high blood pressure is likely causing further cerebral damage.

**Clinical Pearl / High-Yield Fact**
In cases of suspected hypertensive encephalopathy, it's essential to remember the "triple H" rule: Hypertension, Headache, and Altered mental status. If these symptoms are present, and NCCT is negative, the patient should be treated with antihypertensive agents to prevent further cerebral damage.

**Correct Answer:** C.