Equation for a harmonic progressive wave is given by $\mathrm{y}=\mathrm{A}$ $\sin (15 \pi t+10 \pi x+\pi / 3)$ where $x$ is in meter and $t$ is in seconds. This wave is $\ldots \ldots$
(A) Travelling along the positive $\mathrm{x}$ direction with a speed of $1.5 \mathrm{~ms}^{-1}$
(B) Travelling along the negative $\mathrm{x}$ direction with a speed of $1.5 \mathrm{~ms}^{-1} .$
(C) Has a wavelength of $1.5 \mathrm{~m}$ along the $-\mathrm{x}$ direction.
(D) Has a wavelength of $1.5 \mathrm{~m}$ along the positive $\mathrm{x}$ - direction.