PLEASE HELP ME!!!Omar is constructing a square inscribed in a circle. He begins by constructing a circle with a center O and with a diameter connecting points A and C .

What is Omar's next step in the construction?

A
Starting at point A , use the compass with a setting of the length of the radius to mark off the radius four times around the circle.

B
Use OA¯¯¯¯¯ to construct a line tangent to the circle at point A .

C
Construct a perpendicular bisector of AC¯¯¯¯¯ , making it long enough to touch the circle above and below the diameter.

D
Construct a perpendicular bisector of OC¯¯¯¯¯ , making it long enough to touch the circle above and below the diameter.