If x - 1/x = 5 , then x^2 + 1x^2 is?

Answer: Option C

$$\begin{array}{rl}& x-\frac{1}{x}=5\\ & \left[\text{Squaring both sides}\right]\\ & \Rightarrow x^2\text{ + }\frac{1}{x^2}-2=25\\ & \Rightarrow x^2\text{ + }\frac{1}{x^2}=27\end{array}$$