The image formed by a concave mirror is real, inverted and highly diminished (much smaller than the object). The object must be:(a) between pole and focus (b) at focus(c) at the centre of curvature (d) at infinity

(d) At infinity

Explanation

For an object placed at infinity, the image formed by a concave mirror is real and inverted, highly diminished (much smaller than the object), and at the focus $(F)$.