Most ancient and widely followed method of irrigation in India is

✅ EXPLANATION: Surface irrigation is the oldest and most widely followed method of irrigation in India. It is a simple and inexpensive method that involves applying water on the soil surface.

📌Other Options and Explanations:
🔹 Sprinkler irrigation: Sprinkler irrigation is a more modern method of irrigation that involves spraying water over the crop.
🔹 Drip irrigation: Drip irrigation is a more efficient method of irrigation that involves applying water directly to the roots of the crop.