If x^4 + 1x^4 = 14159, then the value of x + 1/x is:

Answer: Option D

$$\begin{array}{rl}& x^4+\frac{1}{x^4}=14159\\ & x^2+\frac{1}{x^2}=\sqrt{14159+2}\\ & x^2+\frac{1}{x^2}=119\\ & x+\frac{1}{x}=\sqrt{119+2}\\ & x+\frac{1}{x}=11\end{array}$$