Final answer:
A large R wave in lead V1 can be indicative of left ventricular hypertrophy.
Step-by-step explanation:
A large R wave in lead V1 on an electrocardiogram (ECG) can be indicative of left ventricular hypertrophy (option a). Left ventricular hypertrophy occurs when the muscle mass of the left ventricle increases, often due to conditions like hypertension or aortic valve disease. This can result in larger electrical activity in lead V1.