## Core Concept
The patient presents with symptoms suggestive of an acute neurological deficit, likely a stroke, given the sudden onset of unconsciousness, hypertension (BP 160/100 mmHg), tachycardia (pulse 120/min), and bilateral extensor plantars. The immediate management of such a patient involves stabilizing vital functions and assessing for potential causes that require urgent intervention.

## Why the Correct Answer is Right
In a patient with suspected stroke, the immediate priority is to ensure airway patency, breathing, and circulation (ABCs). However, given the specifics of this scenario, with the patient being unconscious and having signs of upper motor neuron lesions (bilateral extensor plantars), the next critical step involves assessing and managing potential causes of altered mental status and ensuring no immediate life-threatening conditions such as raised intracranial pressure.

## Why Each Wrong Option is Incorrect
- **Option A:** Administering insulin for hyperglycemia might be necessary given the patient's diabetic history, but it does not directly address the acute neurological presentation.
- **Option B:** While antihypertensives might be considered for severely elevated blood pressure, immediate administration is not typically recommended in the acute stroke setting unless there are specific indications such as aortic dissection, acute myocardial infarction, pulmonary edema, or hypertensive encephalopathy.
- **Option C:** This option is not provided, but typically, an incorrect option might suggest a step that is not immediately relevant to acute stabilization and diagnosis, such as an immediate imaging study without stabilization.

## Clinical Pearl / High-Yield Fact
A crucial step in managing a patient with suspected stroke is to perform a rapid assessment, including a neurological examination and possibly a CT scan of the head to differentiate between ischemic and hemorrhagic stroke, as management differs significantly. Also, remember the "ABCDE" approach: Airway, Breathing, Circulation, Disability, and Exposure.

## Correct Answer: D.