Michael is constructing a circle circumscribed about a triangle. he has partially completed the construction, as shown below. what should be his next step in the construction?
triangle def is shown with two sets of intersecting arc markings on either side of side ef.

connect the arc markings to complete the perpendicular bisector
find the perpendicular bisectors for side df and de
connect three arc markings together to form the triangle
use the intersection of arcs to determine the center of the circle

is the answer a or something else? ?