The block of mass \[M\] moving on a frictionless horizontal surface collides with a spring of spring constant \[k\] and compresses it by length \[L\]. The maximum momentum of the block after collision is

• A. \[\frac{M{{L}^{2}}}{k}\]       
• B. zero
• C. \[\frac{k{{L}^{2}}}{2M}\]                 
• D. \[\sqrt{Mk}L\]