A particle of mass m moving with a velocity \[\vec{V}\] makes a head on elastic collision with another particle of same mass initially at rest. The velocity of the first particle after the collision will be [MP PMT 1997; MP PET 2001; UPSEAT 2001]

• A.          \[\vec{V}\]                    
• B.          \[-\vec{V}\]
• C.          \[-2\vec{V}\]                 
• D.          Zero