If a Convex Lens Were Made Out of Very Thin

Multiple Choice

If a convex lens were made out of very thin clear plastic filled with air, and were then placed underwater where n = 1.33 and where the lens would have an effective index of refraction n = 1, the lens would act in the same way

A) as a concave mirror in air.
B) as a concave lens in air.
C) as a convex lens in air.
D) as a flat refracting surface between water and air as seen from the water side.
E) as the glasses worn by a farsighted person.