If A is the area of the foundation of a retaining wall carrying a load W and retaining earth of weight w per unit volume, the minimum depth (h) of the foundation from the free surface of the earth, is )/(1 + sin )]_________________?

A. h = (W/Aw) [(1 –
B. h = (W/Aw) [(1 + )/(1 + sin )]
C. h = (W/Aw) [(1 – )/(1 + sin )]²
D. h W/Aw) [(1 – )/(1 + sin )]²