Compute the unit binormal vector and torsion of the curve. r(t) = <15t, 8 cos t, 8 sin t>
A. B(t) = <8, -15 sin t, 15 cos t> / sqrt(289), tau = 15/289
B. B(t) = <0, 15 cos t, -15 sin t> / sqrt(289), tau = 1/289
C. B(t) = <0, -15 cos t, -15 sin t> / sqrt(289), tau = -15/289
D. B(t) = <8, 15 sin t, -15 cos t> / sqrt(289), tau = 15/289