Farmer McDonald gives banjo lessons for $20 an hour. One day, he spends 10 hours planting $100 worth of seeds on his farm. Pick the correct answer from the following:
a. he incurs an accounting cost of $100.
b. he incurs an economic cost of $200.
c. he incurs an economic cost of $300.
d. both a and c. 2. In 1, after four months the seeds planted yields $200.