Antonym of WANE

Answer: Option B

Wane : (of a state or feeling) decrease in vigour or extent; become weaker.
Swell : (especially of a part of the body) become larger or rounder in size, typically as a result of an accumulation of fluid.
Prosper : succeed in material terms; be financially successful.
Fatten : make or become fat or fatter.
Widen : make or become wider.

Antonym of Wane is Prosper