A uniformly charged ring of radius $3a$ and total charge $q$ is placed in $x - y$ plane centred at origin. A point charge $q$ is moving towards the ring along the $z$-axis and has speed $v$ at $z = 4a$. The minimum value of $v$ such that it crosses the origin is:\\
(1) $\sqrt { \frac { 2 } { m } } \left( \frac { 1 } { 15 } \frac { q ^ { 2 } } { 4 \pi \epsilon _ { 0 } a } \right) ^ { 1 / 2 }$\\
(2) $\sqrt { \frac { 2 } { m } } \left( \frac { 4 } { 15 } \frac { q ^ { 2 } } { 4 \pi \epsilon _ { 0 } a } \right) ^ { 1 / 2 }$\\
(3) $\sqrt { \frac { 2 } { m } } \left( \frac { 1 } { 5 } \frac { q ^ { 2 } } { 4 \pi \epsilon _ { 0 } a } \right) ^ { 1 / 2 }$\\
(4) $\sqrt { \frac { 2 } { m } } \left( \frac { 2 } { 15 } \frac { q ^ { 2 } } { 4 \pi \epsilon _ { 0 } a } \right) ^ { 1 / 2 }$