This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
Investigation of choice in clinical suspicion of stroke 
Select and explain. 
A. Noncontrast head CT, B. Contrast head CT, C. Noncontrast head MRI, D. Contrast head MRI
A: Noncontrast head CT
Answer: A: Noncontrast head CT 
Explanation: After the clinical diagnosis of stroke is made, an orderly process of evaluation and treatment should follow. The first goal is to prevent or reverse brain injury. Attend to the patient's airway, breathing, and circulation (ABCs), and Treat hypoglycemia or hyperglycemia if identified. Perform an emergency noncontrast head CT scan to differentiate between ischemic stroke and hemorrhagic strokeRef: Harrison 19e pg: 2561