Prove the following statements about a circle of centre O:
(a) (i) No tangent can be drawn to the circle from a point lying strictly inside it.
(b) (ii) Exactly one tangent can be drawn to the circle from a point lying on it.
(c) (iii) Exactly two distinct tangents can be drawn to the circle from a point lying outside it.
(d) Give clear geometrical reasons and, where necessary, supporting constructions for each part.