The velocity of a particle is given by \( v=A \omega \cos (\omega t-k x) \), where \( x \) is position and \( t \) is time. The dimension of \( \frac{k}{\omega} \) will be
(1) \( \left[ M ^{0} L ^{-1} T \right] \)
(2) \( \left[ M ^{0} L ^{-1}\right] \)
(3) \( \left[ M ^{0} L ^{0} T ^{0}\right] \)
(4) \( \left[ ML ^{-1} T \right] \)