$\int \frac{d x}{\sqrt{2^{2}-x^{2}}}=?$

$\frac{1}{x} \sin ^{-1} \frac{x}{a}$

$\frac{1}{a} \sin ^{-1} \frac{x}{a}$

$\frac{1}{x} \sin ^{-1} \frac{a}{x}$

$\frac{1}{a} \sin ^{-1} \frac{a}{x}$

No correct answer