A person starts her own business after quitting her job in which she made $75,000 a year. Expenses include $100,000 for wages and salaries, $15,000 for utilities, $150,000 for materials and supplies, and $5000 for gasoline. She uses her car in her work, for which she paid $16,000 two years earlier. She could rent a similar car for $5000. Implicit costs are
a. $80,000.
b. $91,000.
c. $75,000.
d. $5,000.