A block of 2 kg collides with a horizontal massless spring of force constant k = 2 N/m. The spring gets compressed by 0.4 m. If the coefficient of kinetic friction between the block and the surface is 0.5. The speed of the block at the time of the collision is (g = 10 ms ^–2 )

(a) 3 ms^–1              (b) 1.5 ms^–1                (c) 6 ms^–1                  (d) 4.5 ms^–1