The image formed by a concave mirror
(a) is always real
(b) is always virtual
(c) is certainly real if the object is virtual
(d) is certainly virtual if the object is real.
(c) is certainly real if the
EXPLANATION:
The image formed by a concave mirror may be real or virtual depending upon the position of the object. Hence the option (a) and (b) are wrong. Only the real object placed between the focus and the pole has a virtual image otherwise it is real. The option (d) is not correct.
Hence the only option remaining is (c).