Find the Torsion of the Space Curve A) $\tau = - 1$

Multiple Choice

Find the torsion of the space curve.
- $\mathbf { r } ( \mathrm { t } ) = ( \mathrm { t } - 9 ) \mathbf { i } + ( \ln ( \sec t ) + 8 ) \mathbf { j } - 10 \mathbf { k } , - \pi / 2 < \mathrm { t } < \pi / 2$

A) $\tau = - 1$
B) $\tau = 0$
C) $\tau = 1$
D) Undefined