Concept:A lens with a thinner middle and thicker edges is a concave lens, also called a diverging lens.
Explanation:The shape described is exactly opposite to that of a convex lens.
In this lens, the central part is thinner than its periphery.
Such a lens is known as a concave lens.
When parallel rays of light pass through a concave lens, they spread apart or diverge.
Therefore, this lens is called a diverging lens.
It is not converging, plano-convex, or converging meniscus, because those lenses are thicker at the middle.
Hence, the correct option is diverging.
Answer:A. diverging