On a frictionless surface,a block of mass $M$ moving at speed $V$ collides elastically with another block of same mass $M$ which is initially at rest. After collision,the first block moves at an angle $\theta$ to its initial direction and has a speed $\frac{V}{3}$. The second block's speed after the collision is:

• A
  $\frac{2\sqrt{2}}{3}V$
• B
  $\frac{\sqrt{3}}{2}V$
• C
  $\frac{3}{4}V$
• D
  $\frac{3}{\sqrt{2}}V$