A student is to find the focal length of
(i) a concave mirror
(ii) a convex lens
by focusing the image of a distant object on a screen. He will observe that the screen is on the same side as that of the object in

(a) both the cases
(b) case (i) but not in case (ii)
(c) case (ii) but not in case (i)
(d) neither case (i) nor in case (ii)​