A man of 50kg is standing at one end on a boat   of length 25m and mass 200kg. If he starts    running and when he reaches the other end, he  has a velocity 2ms^-1 with respect to the boat. The final velocity of the boat is (in ms^-1)

• A

  $\frac{2}{5}$

• B

  $\frac{2}{3}$

• C

  $\frac{8}{5}$

• D

  $\frac{8}{3}$