The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy?

The correct option is B No
The law of conservation of energy says that energy cannot be created or destroyed and or in other words total energy of a system remains constant. When a ball starts falling, it's speed increases as it falls. So its kinetic energy keeps increasing ( $K.E$ $=\frac{1}{2}m\times v^2$) as velocity increases and potential energy keeps decreasing ($P.E$ $=m\times g\times h$) as height decreases. So, law of conservation of energy is not violated.