A transverse wave is described by the equation $Y=y_{0} \sin 2 \pi\left(f t-\frac{x}{\lambda}\right)$ The maximum particle velocity is four times the wave velocity if
(a) $\lambda=\frac{\pi y_{0}}{4}$
(b) $\lambda=\frac{\pi y_{0}}{2}$
(c) $\lambda=\pi y_{0}$
(d) $\lambda=2 \pi y_{0}$