Cynthia is constructing a circle inscribed in a triangle. She has partially completed the construction as shown below. What should be her next step in the construction?
Select one:
a. Connect vertex B to the arc markings to complete the angle bisector
b. Use a straightedge to find the angle bisectors for angles A and B
c. Connect three arc markings together to form the triangle
d. Use the arc markings to determine the radius to construct the circle
