What is AB in the figure?
A an altitude
B a perpendicular bisector
C an angle bisector
D none of the above
![What is AB in the figure A an altitude B a perpendicular bisector C an angle bisector D none of the above class=](https://us-static.z-dn.net/files/df9/638f322039c289a026d97a61f542c50d.png)