\( \frac{1}{3} i \) এর বর্গমূল কোনটি?

A \( \pm \frac{1}{\sqrt{3}} \left ( 1 + i \right ) \)

B \( \pm \frac{1}{\sqrt{3}} \left ( 1 - i \right ) \)

C \( \pm \frac{1}{\sqrt{6}} \left ( 1 + i \right ) \)