An equilateral triangle \( OAB \) is inscribed in the parabola \( y^2 = 4x \) with the vertex \( O \) at the vertex of the parabola. Then the minimum distance of the circle having \( AB \) as a diameter from the origin is:
\( 4(6 + \sqrt{3}) \)
\( 2(8 - 3\sqrt{3}) \)
\( 2(3 + \sqrt{3}) \)
\( 4(3 - \sqrt{3}) \)