A wave travelling in the +ve x-direction having displacement along y-direction as 1 m, wavelength 2$\mathrm{\pi }$ m and frequency of $\frac{1}{\mathrm{\pi }}$ Hz is represented by

• A

  $\mathrm{y} = \sin (\mathrm{x}-2\mathrm{t})$

• B

  $\mathrm{y} = \sin (2\mathrm{\pi x}-2\mathrm{\pi f})$

• C

  $\mathrm{y} = \sin (10\mathrm{\pi x}-20\mathrm{\pi t})$

• D

  $y = \sin (2\mathrm{\pi x}+2\mathrm{\pi t})$