A particle passes a point at the instant \( t=0 s \), moving with uniform velocity \( 2 \sqrt{3} m / s \) in the direction. It turns towards east at the instant \( t=8 s \) and moves with uniform velocity \( 6 m / s \). Directic change in its velocity vector is
(A) \( 30^{\circ} \) east of north
(B) \( 60^{\circ} \) south of east
(C) \( 60^{\circ} \) east of north
(D) \( 30^{\circ} \) south of east