Two chords of a circle bisect each other. Then
The chords are any two diameters.
Let AB, CD be the chords intersecting at P such that AP = PB, CP = PD. As PC.PD = PA.PB, we get PA2=PC2 or PA = PC. This means AB = CD, i.e., the chords are of equal length. The perpendicular to AB and CD at their midpoints pass through the centre of the circle.
Unless P is the centre of the circle this cannot happen. Thus AB and CD are diameters of the circle. They need not be mutually perpendicular. Thus option (D) is the correct one.