The correct answer is (d) Extra sensitive soil. Explanation: In soil mechanics, the sensitivity of soil is a measure of its tendency to undergo large deformation or liquefaction when subjected to changes in stress. The sensitivity is defined as the ratio of the undrained shear strength to the drained shear strength of the soil. A sensitivity value between 4 and 8 indicates that the soil is highly sensitive, meaning it has a high tendency to undergo significant deformation or liquefaction under stress. Therefore, soil with a sensitivity between 4 and 8 is classified as extra sensitive soil.
Explanation: In soil mechanics, the sensitivity of soil is a measure of its tendency to undergo large deformation or liquefaction when subjected to changes in stress. The sensitivity is defined as the ratio of the undrained shear strength to the drained shear strength of the soil. A sensitivity value between 4 and 8 indicates that the soil is highly sensitive, meaning it has a high tendency to undergo significant deformation or liquefaction under stress. Therefore, soil with a sensitivity between 4 and 8 is classified as extra sensitive soil.