Suppose that the market for corn is initially in equilibrium and is perfectly competitive. The demand curve can be expressed as P =10 Q ; the supply curve can be expressed as P =0.25 Q . Quantity is expressed in millions of bushels. Now suppose that the federal government imposes a price floor of $3 per bushel of corn. What is the dead-weight loss (per million bushels) associated with the price floor when the least efficient producers are active?

a) $9.375

b) $2.25.

c) $1.

d) $0.63.

The answer is A. I don't know why. Please explain.