For the same value of φ, the backfill is partly submerged to height H2 and the backfill is moist to a depth H1. Find the lateral pressure intensity at the base of wall.

• A. pa=Ka γH1-Ka γ’ H2+γw H2
• B. pa=Ka γH1+Ka γ’ H2+γw H2
• C. pa=Ka γH1+γw H2
• D. pa=Ka γH1+Ka γ’ H2