The diagram shows a ray of light being reflected by a mirror. Which row gives the correct names for $x$, $y$ and $Z$?
- A$x$: angle of incidence, $y$: angle of reflection, $Z$: normal
- B$x$: angle of incidence, $y$: angle of reflection, $Z$: principal focus
- C$x$: angle of reflection, $y$: angle of refraction, $Z$: normal
- D$x$: angle of reflection, $y$: angle of refraction, $Z$: principal focus