**Core Concept**
The initial clinical assessment of a patient presenting with acute neurological symptoms, such as sudden weakness, numbness, or difficulty speaking, requires a prompt identification of the underlying cause. The Ischemic Stroke (IO) is a medical emergency that necessitates immediate diagnosis and treatment to prevent further brain damage. The identification of the IOC for stroke is crucial in guiding the initial management and treatment decisions.

**Why the Correct Answer is Right**
The IOC for stroke is Computed Tomography (CT) scan, specifically non-contrast CT. This imaging modality is widely available, quick, and sensitive for detecting acute ischemic strokes. The CT scan can identify areas of ischemia or infarction in the brain, which helps in differentiating between ischemic and hemorrhagic strokes. The non-contrast CT scan does not require the use of contrast agents, making it a safe option for patients with renal insufficiency or contrast allergy.

**Why Each Wrong Option is Incorrect**
**Option A:** MRI is not the IOC for stroke in the acute setting due to its longer scanning time and limited availability compared to CT.
**Option B:** CT Angiography (CTA) is a useful tool for identifying vascular occlusions or stenosis but is not the primary IOC for stroke diagnosis.
**Option C:** ECG is essential in identifying cardiac arrhythmias or myocardial infarction but is not the IOC for stroke diagnosis.

**Clinical Pearl / High-Yield Fact**
Remember that the ABCD2 score (Age, Blood pressure, Clinical features, Duration of symptoms, and Diabetes) can be used to predict the risk of stroke recurrence in patients with transient ischemic attack (TIA) but is not a substitute for imaging studies in diagnosing stroke.

**Correct Answer:** C.