A transever sine wave of amplitude 10 cm and wavelength 200 cm travels from left to right along a long horizontal stretched, string is at the origin and is moving downward. Then the equation of the wave will be ( in CGS system )
A. `y = 10 sin (0.01 pi xx - pit)`
B. `y = 10 sin (pit- 0.01 pi xx)`
C. `y = 10 sin (0.02 pi xx- 0.01 pi t)`
D. `y = 10 sin (pi t - 0.02 pi xx)`
