Match the given cases of image formation with the position of the object:
I - c, II - d, III - b, IV - a
An object is placed at C, since the size of the object = size of the image.
Since the size of the object > size of the image, the object is kept beyond C.
Since rays meet at infinity, the object is kept at the focus.
Since rays meet beyond the mirror, the image is virtual, the object is kept between focus and pole.