The rise in water level if a stone weighing 300 g instead of 200 g were dropped in the beaker would likely be an additional 200 ml. So, the correct answer is A. 200 ml.
This question seems to relate to the concept of water displacement, according to Archimedes' principle. When an object is submerged in water, it displaces an amount of water equal to its own volume.
The initial stone weighs 200 g, and it causes the water level to rise by 400 ml. To find the rise in water level if a stone weighing 300 g were dropped instead, you can consider the relationship between the weight of the stone and the volume of water displaced.
Assuming the stones have the same density, the increase in weight from 200 g to 300 g represents a 50% increase. This suggests that the increase in water displaced will also be proportional to the increase in weight.
If the 200 g stone caused a 400 ml rise, a 50% increase might lead to a 50% increase in the water level rise:
50% of 400 ml = 0.5 * 400 ml = 200 ml
Therefore, the rise in water level if a stone weighing 300 g instead of 200 g were dropped in the beaker would likely be an additional 200 ml. So, the correct answer is A. 200 ml.