An expression of energy density is given by $u=\frac{\alpha}{\beta} \sin \left(\frac{\alpha x}{k t}\right)$, where $\alpha, \beta$ are constants, $x$ is displacement, $k$ is Boltzmann constant and $t$ is the temperature. The dimensions of $\beta$ will be.

• A

  $\left[ ML ^{2} T ^{-2} \theta^{-1}\right]$

• B

  $\left[ M ^{0} L ^{2} T ^{-2}\right]$

• C

  $\left[ M ^{0} L ^{0} T ^{0}\right]$

• D

  $\left[ M ^{0} L ^{2} T ^{0}\right]$