When a Market or a Policy Achieves a ""Pareto-Optimum"", Then

When a market or a policy achieves a ""Pareto-Optimum"", then

A) it is still possible to make one additional person better off, without making others worse-off.
B) the economy's Real GDP is equally divided among all decision-makers.
C) it is no longer possible to make one additional person better-off without making another person worse-off.
D) it is possible to make all decision makers in the economy better-off with a new policy choice.
E) none of theabove.