$\text{If } \tan A = \frac{1}{\sqrt{x(x^2 + x + 1)}}, \; \tan B = \frac{\sqrt{x}}{\sqrt{x^2 + x + 1}} \quad \text{and} \quad \tan C = (x^{-3} + x^{-2} + x^{-1})^{1/2}, \; 0 < A, B, C < \frac{\pi}{2}, \text{ then}$ $A + B \text{ is equal to:}$
\( C \)
\( \pi-C \)
\( \dfrac{\pi}{2}-C \)
\( 2\pi-C \)
