Evaluate ${\displaystyle \underset{7}{\overset{13}{}}}2\frac{1}{x^2\sqrt[\phantom{2}]{x^2-9}}dx$

Setect one:

a$.\frac{2}{9}cos$

b$.\frac{2}{9},\frac{\sqrt[\phantom{2}]{x^2-9}}{x}$

c$.\frac{4}{819}\sqrt[\phantom{2}]{10}$

d$.-\frac{2}{9},\frac{\sqrt[\phantom{2}]{x^2-9}}{x}$