The optician prescribes a corrective lens of power +2.5D. What does this mean?

A

The lens is a combo of 2 convex lenses,
with powers 2D and 0.5D

B

The lens is a combo of 2 concave lenses,
with powers 2D and 0.5 D

C

The lens is convex with power 2D

D

The lens is concave with power 2.5D