The point A has coordinates (−1, 6) and the point B has coordinates (7, 2).

i. Find the equation of the perpendicular bisector of AB, giving your answer in the form y = mx + c.

ii. A point C on the perpendicular bisector has coordinates (p, q). The distance OC is 2 units, where O is the origin. Write down two equations involving p and q and hence find the coordinates of the possible positions of C.