CONCEPT:
- Plane mirror: This mirror is straight without any inward or outward curve.
- It forms a virtual image and upright image which is of size as same as the object.
- The bathroom mirrors are an example.
- Concave mirror: The mirrors curved inside on the reflecting side are called concave mirrors.
- These mirrors produce a real, inverted, and magnified image of the object.
- These are used in reflecting telescopes, shaving mirrors, and ophthalmoscope.
- Convex mirror: It is an outward curved mirror that produces a diminished image.
- Convex mirrors either diverge a parallel beam of light into all directions or gather light from all directions and produce a parallel beam out of it.
EXPLANATION:
- Following are the reasons as to why a convex mirror is used as a rearview mirror in the vehicle

- The image formed by the convex mirror is virtual and erect in contrast to that of the real but inverted image of the concave mirror.
- It gathers light from all directions and aligns it as a parallel beam so that it provides a wider view to the viewer. That's why the convex mirror is used as a rear-view mirror in vehicles. So option 2 is correct.


