At time t = 0, two point objects A and B respectively are at pole and centre of curvature of a fixed concave mirror of focal length f. The velocity vectors of A and B are always vector vA = ui and vB = -ui respectively, where 'i' is unit vector along principal axis directed from pole towards focus and u is a positive constant.
The distance between images of A and B will be 4f at time t =
(A) f/√2u
(B) √2f/u
(C) f/2u
(D) f/4u
