The Market Demand Function for Wheat Is Q^d = 10

The market demand function for wheat is Q^d = 10 - 2P and the market supply function is Q^s = 4P - 2,both measured in billions of bushels per year.Suppose the government wants to increase the price of wheat to $3/bushel and they impose a voluntary production reduction program to achieve their goal.What is the size of the producer surplus?

A) $8 billion
B) $4.5 billion
C) $12.5 billion
D) $6.5 billion