Two points of a rod move with velocities \[3v\] and \[v\] perpendicular to the rod and in the same direction separated by a distance '\[r\]'. The angular velocity of the rod is

• A. \[\frac{3v}{r}\]            
• B. \[\frac{4v}{r}\]
• C. \[\frac{5v}{r}\]            
• D. \[\frac{2v}{r}\]