Let \( \tan A, \tan B \), where \( A, B \in \left( -\frac{\pi}{2}, \frac{\pi}{2} \right) \), be the roots of the quadratic equation \( x^2 - 2x - 5 = 0 \). Then \( 20\sin^2\!\left( \frac{A + B}{2} \right) \) is equal to:
\( 10 + \sqrt{10} \)
\( 10 - 2\sqrt{10} \)
\( 10 - 3\sqrt{10} \)
\( 10 - \sqrt{10} \)