Nature of the image is not affected by the position of object in a
convex mirror.
Explanation for the correct option(s) -
Option (a)
The nature of the image is not affected by the position of an object in a plane mirror as a plane mirror always forms a virtual and erect image that is the same size as that of the object.
Option (c)
The nature of the image is not affected by the position of an object in a convex mirror as a convex mirror always forms a virtual and erect image of the object.
Explanation for the incorrect option(s) -
Option (b)
A concave mirror forms a virtual image when the object is placed between the pole and the focus of the mirror. It forms a real image when an object is placed beyond the focus of the mirror.
Option (d)
A plane mirror and convex mirror is the correct answer.
Hence, option (a) and option (c) are the correct answers.