A string of negligible mass going over a clamped pulley of mass m supports a block of mass M as shown in the figure. The force on the pulley by the clamp is given by [IIT-JEE 2001]

• A. \[\sqrt{2}Mg\] 
• B. \[\sqrt{2}mg\]
• C. \[\sqrt{{{(M+m)}^{2}}+{{m}^{2}}}g\]
• D.   \[\sqrt{{{(M+m)}^{2}}+{{M}^{2}}}g\]