The work done by a gas molecule in an isolated system is given by $W = \alpha \beta^{2} e^{-\frac{x^{2}}{\alpha kT}}$,where $x$ is the displacement,$k$ is the Boltzmann constant,$T$ is the temperature,and $\alpha$ and $\beta$ are constants. Then the dimension of $\beta$ will be:

• A
  $[M L^{2} T^{-2}]$
• B
  $[M L T^{-2}]$
• C
  $[M^{2} L T^{2}]$
• D
  $[M^{0} L T^{0}]$