Correct option is A
Mohr-Coulomb failure theory:
Soil generally fails in shear.
At the failure surface, shear stress reaches the shear strength (T) of the soil.
The resistance that the soil offers during deformation is mainly due to the shear resistance between the particles at their contact points at the failure surface.
No crushing of individual particles takes place.
According to the Mohr-Coulomb failure criterion, the shear strength of the soil can be expressed as:
τ = c + σ Tan ϕ
So from the shear strength Equation of Mohr coulomb, shear strength depends on both normal force and angle of internal friction.
