Let a circle passes through origin and the points $\mathrm { A } ( - \sqrt { 2 } \alpha , 0 ) , \mathrm { B } ( 0, \sqrt { 2 } \beta )$, where $\alpha$ and $\beta$ are non zero real parameters, such that its radius is 4 . Then the radius of locus of centroid of triangle $O A B$ is\\
(A) $\frac { 2 } { 3 }$\\
(B) $\frac { 4 } { 3 }$\\
(C) $\frac { 11 } { 3 }$