A vertical spring with force constant 'k' is fixed on a table. A ball of mass 'm' at a height 'h' above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance 'd'. The net work done in the process is

• A

  $mg\left(h+d\right)+\frac{1}{2}k{d}^2$

  
   

• B

  $mg\left(h+d\right)=\frac{1}{2}k{d}^2$

  
   

• C

  $mg\left(h-d\right)-\frac{1}{2}k{d}^2$

  
   

• D

  $mg\left(h-d\right)+\frac{1}{2}k{d}^2$