Natalie is completing construction of an equilateral triangle inscribed in a circle, as shown below: What should be the next step in her construction?

Circle A is drawn with point B marked on the circle and a compass opened to the length of segment AB.

Construct a line perpendicular to the line AB to create four congruent quadrants.
Construct six equal sections around the circle using the original radius as a guide.
Construct another point C anywhere on the circle to be the third vertex of her triangle.
Draw arcs above and below line AB to show where the triangle sides meet.

Question

Natalie is completing construction of an equilateral triangle inscribed in a circle, as shown below: What should be the next step in her construction?

Circle A is drawn with point B marked on the circle and a compass opened to the length of segment AB.

Construct a line perpendicular to the line AB to create four congruent quadrants.
 Construct six equal sections around the circle using the original radius as a guide.
 Construct another point C anywhere on the circle to be the third vertex of her triangle.
 Draw arcs above and below line AB to show where the triangle sides meet.