Which defines a concave mirror?

A concave mirror curves inward with the edges of the mirror pointing towards the viewer.
A concave mirror curves inward with the edges of the mirror pointing towards the viewer.

A concave mirror curves outward with the edges of the mirror pointing away from the viewer.
A concave mirror curves outward with the edges of the mirror pointing away from the viewer.

A concave mirror curves outward with the edges of the mirror pointing towards the viewer.
A concave mirror curves outward with the edges of the mirror pointing towards the viewer.

A concave mirror curves inward with the edges of the mirror pointing away from the viewer

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