The correct answer is C. 0.95.
Relative density is a measure of how closely packed the particles of a soil are. It is defined as the ratio of the dry density of the soil to the maximum dry density of the soil. The maximum dry density is the highest density that a soil can achieve when it is compacted.
A compacted dense sand is a soil that has been compacted to a high density. This type of soil is often used in construction because it is strong and stable. The relative density of a compacted dense sand is typically between 0.95 and 1.0.
Option A is incorrect because the relative density of a compacted dense sand is typically greater than 0.4.
Option B is incorrect because the relative density of a compacted dense sand is typically greater than 0.6.
Option D is incorrect because the relative density of a compacted dense sand is typically less than 1.20.