The correct answer is D. Franki pile.
A Franki pile is a type of foundation pile that is driven into the ground by a drop hammer. The pile is made of concrete and has a bulb filled with concrete at its lower end. The bulb helps to distribute the load of the structure over a larger area, which makes it more stable.
Simplex piles are driven into the ground by a vibratory hammer. They are made of steel or concrete and have a smooth cylindrical shaft.
Mac-Arthur piles are driven into the ground by a hydraulic hammer. They are made of steel and have a tapered shaft.
Raymond piles are driven into the ground by a drop hammer. They are made of concrete and have a square or rectangular shaft.
Here is a diagram of a Franki pile:
The pile is driven into the ground by a drop hammer. The hammer is raised and then dropped onto the pile, which drives it into the ground. The pile is driven until it reaches a predetermined depth.
Once the pile is in place, concrete is poured into the bulb at the lower end of the pile. The concrete helps to distribute the load of the structure over a larger area, which makes it more stable.
Franki piles are often used in foundation construction for heavy structures, such as buildings and bridges. They are also used in marine construction.