The correct answer is A. 5%.
A good quality stone absorbs water less than 5%. This is because the stone is dense and has a low porosity. The porosity of a material is the percentage of its volume that is made up of pores. The higher the porosity, the more water a material will absorb.
Option B, 10%, is too high. A stone that absorbs 10% of its weight in water is considered to be of poor quality.
Option C, 15%, is also too high. A stone that absorbs 15% of its weight in water is considered to be of very poor quality.
Option D, 25%, is the highest option. A stone that absorbs 25% of its weight in water is considered to be of extremely poor quality.
In general, stones that are used for construction or landscaping should absorb no more than 5% of their weight in water. This is because water can cause stones to expand and crack, which can lead to structural problems.