Pick up the correct statement from the following: A. The dry density reduces by addition of water after attaining optimum moisture content B. The line joining the peak of three moisture content graphs obtained by using three compactive energies, is called line of optimus C. Well graded coarse grained soils can be compacted to a very high density as compared to fine grained soils D. All the above

The correct answer is D. All the above.

Option A is correct because the dry density of a soil decreases with increasing water content after the optimum moisture content is reached. This is because the water molecules fill up the voids between the soil particles, which makes it more difficult for the soil particles to pack together tightly.

Option B is correct because the line joining the peak of three moisture content graphs obtained by using three compactive energies is called the line of optimum. This line represents the moisture content at which the soil has the highest dry density for a given compactive energy.

Option C is correct because well graded coarse grained soils can be compacted to a very high density as compared to fine grained soils. This is because the coarse grained soils have larger voids between the particles, which allows them to pack together more tightly.

Here is a diagram that shows the relationship between dry density and water content for a typical soil:

[Diagram of dry density vs. water content]

The optimum moisture content is the point at which the dry density is highest. The line of optimum is the line that joins the peak of the three moisture content graphs.

I hope this explanation is helpful!