$A$ wave travelling along the $x$-axis is described by the equation $y(x, t) = 0.005 \cos(\alpha x - \beta t)$. If the wavelength and the time period of the wave are $0.08 \ m$ and $2.0 \ s$,respectively,then $\alpha$ and $\beta$ in appropriate units are:

• A
  $\alpha = 12.5\pi, \beta = \frac{\pi}{2}$
• B
  $\alpha = 25\pi, \beta = \pi$
• C
  $\alpha = \frac{0.08}{\pi}, \beta = \frac{2}{\pi}$
• D
  $\alpha = \frac{0.04}{\pi}, \beta = \frac{1}{\pi}$