Answer:
Option B. perpendicular bisector of side AB
Step-by-step explanation:
we know that
The circumcenter is the intersection point of the perpendicular bisectors of a triangle
so
In this problem
The circumcenter O is the intersection point of perpendicular bisector of side AB and perpendicular bisector of side BC
OA=OB=OC ------> the radius of the circle that passes through all three of the triangle's vertices.
therefore
Option B. perpendicular bisector of side AB
