An equilateral triangle circumscribed about a circle equilateral triangle circumscribed about a circle mean a circle inside an equilateral triangle. We don't have circle inside the triangle in our graph.
B. An equilateral triangle inscribed in a circle
Yes equilateral triangle is inscribed in a circle BDE
C. The circumcenter of an equilateral triangle
Circumcenter is not equidistant from the vertices of triangle
