Consider two physical quantities $$A$$ and $$B$$ related to each other as $$E = \frac{B - x^2}{At}$$ where $$E$$, $$x$$ and $$t$$ have dimensions of energy, length and time respectively. The dimension of $$AB$$ is

A

$$L^{-2}M^{1}T^{0}$$

B

$$L^{2}M^{-1}T^{1}$$

C

$$L^{-2}M^{-1}T^{1}$$

D

$$L^{0}M^{-1}T^{1}$$