The correct answer is option 'D', zero.

Explanation:
When an object is floating in a fluid, such as water, it experiences two main forces: the weight of the object (due to gravity) and the buoyant force exerted by the fluid.

- Weight of the cork:
The weight of an object is given by the formula: weight = mass × acceleration due to gravity. In this case, the mass of the cork is given as 10 g, which is equivalent to 0.01 kg. The acceleration due to gravity is approximately 9.8 m/s^2. Therefore, the weight of the cork is calculated as follows:
weight = (0.01 kg) × (9.8 m/s^2) = 0.098 N

- Buoyant force on the cork:
The buoyant force exerted by a fluid on an object is equal to the weight of the fluid displaced by the object. When an object floats, the buoyant force is equal to the weight of the object. This is known as Archimedes' principle.

Since the cork is floating on water, it displaces an amount of water equal to its own weight. Therefore, the buoyant force on the cork is equal to its weight, which is calculated as 0.098 N.

- Net force on the cork:
The net force acting on the cork is the vector sum of all the forces acting on it. In this case, the weight of the cork and the buoyant force on the cork are equal in magnitude but opposite in direction. Therefore, the net force on the cork is the difference between these two forces, which is zero.

Hence, the correct answer is option 'D', zero.