A cannon ball is fired with a velocity $200 {\mathrm{ms}}^{-1}$ at an angle of 60° with the horizontal. At the highest point of its flight, it explodes into 3 equal fragments, one going vertically upwards with a velocity $100 {\mathrm{ms}}^{-1}$, the second one falling vertically downwards with a velocity $100 {\mathrm{ms}}^{-1}$. The third fragment will be moving with a velocity

• A

  $100 {\mathrm{ms}}^{-1}$ in the horizontal direction

• B

  $300 {\mathrm{ms}}^{-1}$ in the horizontal direction

• C

  $300 {\mathrm{ms}}^{-1}$ in a direction making an angle of 60° with the horizontal

• D

  $200 {\mathrm{ms}}^{-1}$ in a direction making an angle of 60° with the horizontal