The correct option is D Squat low with hands on the knees and head between the hands.
During lightning, squat low on the ground. Place your hands on your knees with your head between the hands. This position will make you a small target to be struck as the surface area of the body is very low in this case and the height above the ground level is also very less.
In lightning, charges can also flow along the top of the ground upto a distance of about 100 feet. Squatting position as mentioned above will also reduce the surface area of the body that is in direct contact with the ground.