The Three-Cylinder Mill Revolutionized Sugar Production Around the Year 1500

The three-cylinder mill revolutionized sugar production around the year 1500, allowing sugar cane to be crushed rapidly using animal power (before then, the cane had to be ground by hand with a mortar-and-pestle) . It took only three slaves to operate the machine, a small fraction of what it took to do the same job by hand. What happened to the price of slaves for sugar production?

A) It increased, because the marginal product of labor increased.
B) It decreased, because you needed fewer slaves to crush your sugar cane.
C) It stayed the same, because the factor from (a) balances out the factor from (b) .
D) It decreased, because the marginal product of labor increased. .