To determine the amount of surplus wool generated by the floor price of $6, we need to find the difference between the quantity supplied and the quantity demanded at that price.
Looking at Exhibit 16.3, we can see that the quantity supplied at a price of $6 is 250 million pounds, while the quantity demanded is 160 million pounds.
Therefore, the surplus of wool generated by the price floor is:
250 million pounds - 160 million pounds = 90 million pounds
So the answer is D) 90 million pounds.