Assertion(A) : The coefficient of ${\mathrm{x}}^5$ in the expansion ${\log }_{\mathrm{e}}\left(\frac{1+\mathrm{x}}{1-\mathrm{x}}\right)$ is $\frac{2}{5}$

Reason(R) : The equality 
$\log \left(\frac{1+\mathrm{x}}{1-\mathrm{x}}\right)=2\left[\mathrm{x}+\frac{{\mathrm{x}}^2}{2}+\frac{{\mathrm{x}}^3}{3}+\frac{{\mathrm{x}}^4}{4}+\dots \dots \infty \right]$ is valid for $\left|\mathrm{x}\right|<1$

A is false, R is true

A is true, R is true and R is correct explanation of A

A is true, R is false

A is true, R is true and R is not correct explanation of A