The correct answer is C. self-weight of dam.
A gravity dam is a type of dam that relies on its own weight to resist the force of water. The dam is typically made of concrete or masonry and is built in a curved shape to increase its resistance to overturning. The self-weight of the dam is the major resisting force because it provides a downward force that counteracts the upward force of the water.
Water pressure is the force exerted by water on a surface. The water pressure at a given point is equal to the weight of the water above that point. The water pressure increases with depth, so the water pressure at the bottom of a dam is much greater than the water pressure at the top of the dam.
Wave pressure is the force exerted by waves on a surface. The wave pressure is equal to the mass of the water in a wave multiplied by the acceleration due to gravity. The wave pressure increases with the height of the wave and the speed of the wave.
Uplift pressure is the force exerted by water on a surface from below. The uplift pressure is equal to the weight of the water above that surface. The uplift pressure can be significant in dams that are built on porous foundations, as the water can flow through the foundation and exert an upward force on the dam.