For better strength and stability, the fine grained soils and coarse grained soils are compacted respectively as A. dry of OMC and wet of OMC B. wet of OMC and dry of OMC C. wet of OMC and wet of OMC D. dry of OMC and dry of OMC where OMC is optimum moisture content

The correct answer is: A. dry of OMC and wet of OMC.

Fine-grained soils are compacted dry of OMC to achieve maximum strength and stability. This is because fine-grained soils are more susceptible to compaction when they are wet. When fine-grained soils are compacted wet of OMC, they can become over-compacted, which can lead to decreased strength and stability.

Coarse-grained soils are compacted wet of OMC to achieve maximum strength and stability. This is because coarse-grained soils are less susceptible to compaction when they are wet. When coarse-grained soils are compacted dry of OMC, they can become under-compacted, which can lead to decreased strength and stability.

The optimum moisture content (OMC) is the moisture content at which a soil has the maximum dry density and minimum void ratio. The OMC is determined by performing a compaction test.

The following is a brief explanation of each option:

• Option A: dry of OMC and wet of OMC. This is the correct answer.
• Option B: wet of OMC and dry of OMC. This is incorrect. Fine-grained soils are compacted dry of OMC, while coarse-grained soils are compacted wet of OMC.
• Option C: wet of OMC and wet of OMC. This is incorrect. Fine-grained soils are compacted dry of OMC, while coarse-grained soils are compacted wet of OMC.
• Option D: dry of OMC and dry of OMC. This is incorrect. Fine-grained soils are compacted dry of OMC, while coarse-grained soils are compacted wet of OMC.