Automaker Henry Ford famously paid high wages to his workers. In 1914, he offered $5 a day (about $107 today) for assembly line work. The offer resulted in long lines for Ford jobs, little worker turnover, and high-quality workers. Paying above-market wages may improve profits better than piece rate incentives if:________

a. supported by intrinsic motivation.
b. product quality is not a concern.
c. environmental risks are not a factor.
d. worker effort is easily observable.