A transverse wave of amplitude `0.5 m` and wavelength 1 m and frequency 2 Hz is propagating in a string in the negative x - direction. The expression for this wave is [
A. `y(x,t)=0.5 sin (2 pi x-4 pi t)`
B. `y(x,t)=0.5 cos (2 pi x+ 4 pi t)`
C. `y(x,t)=0.5 sin (pi x-2 pi t)`
D. `y(x,t)=0.5 cos (2 pi x + 2 pi t)`
