System shown in figure is released from rest . Pulley and spring is mass less and friction is absent everywhere. The speed of `5 kg` block when `2 kg` block leaves the constant of with ground is (force constant of spring `k = 40 N//m and g = 10 m//s^(2))`
A. `sqrt(2)m//s`
B. `2sqrt(2)m//s`
C. `2m//s`
D. `4sqrt(2) m//s`
