Which of the following units denotes the dimensions $\frac{M{L}^2}{Q^2}$, where $Q$ denotes the electric charge?

From the dimensional consideration, which of the following equations is correct? (Here $T=$time period, $R=$radius, $M=$mass and $G=$gravitational constant)

$\int \frac{dx}{\sqrt{2ax-x^2}}=a^{\mathrm{n}}{\sin }^{-1}\left[\frac{x}{a}-1\right]$

Find the value of $n$. (Solve using dimensional analysis)