The correct option is C It won't be formed at all.
The mirror is the light source in a compound microscope. A compound microscope has a plano concave mirror. It is a type of mirror with one surface plane and the other concave. The plane surface reflects the sunlight and the concave plane reflects light from an artificial source. If the mirror is removed from a compound microscope, there will be no light available for the lens to create a magnified image.