Let us consider a system of units in which mass and angular momentum are dimensionless. If the length has dimension of L, then the dimension of power is
Correct option is B. $$L^{-4}$$
$$[M] = mass = M^0L^0T^0$$
$$J(R)$$ = angular momentum
$$e = mvR = \dfrac{mL^2}{T}$$
$$m \rightarrow$$ Dimensionless
$$T = L^{2}$$
L is also Dimensionless
Now $$P = mv = \dfrac{mL}{T}$$
m is dimensionless
$$[P] = L^{-1}$$
Power = $$\dfrac{mL^2}{T^2 . T} = \dfrac{L^2}{L^2T^2L} = L^{-4}$$