Which of the following statements correctly describes a double concave lens?

1. AIt is thinner at the edges and thicker in the middle; it converges light rays.
2. BIt is used to focus light to a single point.
3. CIt is equally thick at the center and edges; it neither converges nor diverges light.
4. DIt is thicker at the edges and thinner in the middle; it diverges light rays.