Which Is an Example of a Change in Product Demand

Which is an example of a change in product demand that increases labor demand?

A) Access to computers increases the productivity of mail-order businesses, thus increasing the demand for their workers.
B) Tourism increases in popularity, increasing the demand for workers at tourist resorts.
C) A decrease in the price of trucks decreases the cost of transporting goods, thus increasing the demand for truckers.
D) A change in work rules increases output per worker in the auto industry, thus increasing the demand for auto workers.