Match the following.

Column-I		Column-II
A)	Locus of point of intersection of perpendicular tangents to $y^2+4ax=0$ is	P)	x = a
B)	Locus of P whose chord of contact subtends a right angle at vertex of  $y^2+4ax=0$ is	Q)	x = 4a
C)	Common normal to $y^2+4ax=0$ and $x^2=4ay$	R)	x + 3a = 0
D)	Locus of P, if tangents from P to the parabola $y^2=4ax$ intersect coordinate axis in concyclic points	S)	x - y = 3a