Identify whether each of the following statements best illustrates the concept of consumer surplus, producer surplus, or neither.

a. I was willing to pay up to $68 for a used textbook and even though the seller was willing to go as low as $61 in order to sell it, we couldn't reach a deal because the government imposed a price ceiling of $56 on the sale of textbooks.
b. Even though I was willing to pay up to $115 for a used laptop, I bought a used laptop for only $110.
c. I sold a watch for $59, even though I was willing to go as low as $53 in order to sell it.