per unit run exerted by the Total pressure on the vertical face of a retaining wall of height retained earth weighing per unit volume, is___________________?

A. wh [(1 – )/(1 + sin )]
B. wh² [(1 – )/(1 + sin )]
C. wh² [(1 – )/2(1 + sin )]
D. wh² [(1 – )/3(1 + sin )]