Which of the following is the best example of a marginal change?
A. The price of housing in Denver increased by 6 percent last year.
B. Kim gets a big promotion at work. She also gets a raise from $35,000 per year to $55,000 per year.
C. Mark graduates from college and takes a job. His income increases from $10,000 per year to $35,000 per year.
D. A drought hits the upper Midwest and the price of wheat increases from $4.00 per bushel to $6.50 per bushel.