If p is the net upward pressure on a square footing of side b for a square column of side a, the maximum bending moment is given by

A. \({\rm{B}}.{\rm{M}} = \frac{{{\rm{pb}}\left( {{\rm{c}} - {\rm{a}}} \right)}}{4}\)

B. \({\rm{B}}.{\rm{M}} = \frac{{{\rm{pb}}{{\left( {{\rm{b}} - {\rm{a}}} \right)}^2}}}{4}\)

C. \({\rm{B}}.{\rm{M}} = \frac{{{\rm{pb}}{{\left( {{\rm{b}} - {\rm{a}}} \right)}^2}}}{8}\)

D. \({\rm{B}}.{\rm{M}} = \frac{{{\rm{pb}}\left( {{\rm{b}} + {\rm{a}}} \right)}}{8}\)