A real image is obtained only in case of concave mirror or convex lens.
So option (D) is out.
Rest choices involve concave mirror only. So i will analyse for concave mirror only(exclude convex lens)
Object is placed at -2.0m.
Since image is small, diminished image is formed.
For concave mirror,
- a diminished image is formed when object is beyond 2F
(Rest cases are:
- a point image is formed when object is at infinity(not the case here)
- a enlarged image is formed when object is between F and 2F.(not the case)
- a image of same size is formed when object is at 2F (not the case))
So 2m is beyond 2F. That means F is less than (2/2)m or 1m.
So option A and C are correct.
Option B is not fully correct as greater than 0.5 doesn't mean less than 1m. So only answers are A and C.