Given the axis of a parabola lies along the x-axis. If its vertex and focus are at a distance 2 and 4 respectively from the origin on the positive x-axis, then which of the following points does not line on the parabola?
(a) (4,−4)
(b) (5,2√6 )
(c) (8,6)
(d) (6,4√2 )
.