A simple harmonic wave is represented by the relation $y(x, t)=a_{o} \sin 2 x\left(v t-\frac{x}{\lambda}\right)$
If the maximum particle velocity is three times the wave velocity, the wavelength $\lambda$ of the wave is
(a) $\pi a_{a} / 3$
(b) $2 \pi a_{o} / 3$
(c) $\pi a_{o}$
(d) $\pi a_{e} / 2$