The correct answer is (b) Saturated unit weight.
In the context of the question, the term “sudden drawdown condition” refers to a situation where there is a rapid decrease in water level, such as during a flood or a sudden release of water. In such a scenario, the weight of the soil component is considered as the saturated unit weight.
Saturated unit weight is the unit weight of soil when it is fully saturated with water. It is an important parameter in geotechnical engineering, as it affects the stability of slopes, foundations, and other structures. The saturated unit weight is typically higher than the dry unit weight, as the presence of water increases the overall weight of the soil.
In contrast, dry unit weight refers to the unit weight of soil when it is completely dry, bulk unit weight refers to the weight of soil per unit volume including the air space, and submerged unit weight refers to the unit weight of soil when it is submerged in water.