A. 8

B. 4

C. 2

D. 1

If the distances from the origin to the centres of three circles x^{2}+y^{2}-2k, x=c^{2} (i=1,2,3),are in G.P, then the lengths of the tangents drawn to them from any point on the circle x^{2} + v^{2} = c^{2} are in

If α, β are the roots of x^{2}+ ax+b=0 and γ, δ are the roots y^{2}+cx+d=0 then the equation of the circle having the line joining (α, γ), (β, δ) as diameter is

The least distance of the line 8x-4y+73=0 from the circle 16x^{2}+16y^{2}+48x-8y-43=0 is

The equation of the circle with centre (-1, 1) and touching the circle x^{2}+y^{2}-4x+6y-3=0 externally is

The orthocentre of triangle formed by the lines x + 3y = 10 and 6x<sup>2</sup> + xy - y<sup>2</sup> = 0 is: