For classical utilitarians who value “the greatest amount of good for the greatest number,” Option A is the perfect choice because the country is at its wealthiest
What is the Ideal Economic Pie?
Kareen Movsesyan

You are mistaken in thinking that A is the most utilitarian choice. Since the upper quintile is by def. a minority it has a disproportionate amount of happiness (wealth) for its number.

Greatest good for the greatest number is an inherently redistributive concept. A is concentrative.

The amount of aggregate wealth is meaningless under utilitarian principles since within the aggregate there can be great imbalances.