If $z = \cos \frac{\pi}{6} + i\sin \frac{\pi}{6}$,then:

• A
  $|z| = 1, \arg z = \frac{\pi}{4}$
• B
  $|z| = 1, \arg z = \frac{\pi}{6}$
• C
  $|z| = \frac{\sqrt{3}}{2}, \arg z = \frac{5\pi}{24}$
• D
  $|z| = \frac{\sqrt{3}}{2}, \arg z = \tan^{-1} \frac{1}{\sqrt{2}}$