Is the difference between the price of a good and the cost to make the good, on a per product basis; and, it is usually expressed as a percentage.
a. incremental profit
b. net income
c. profit margin
d. gross margin

The correct answer for this question is "c. Profit margin." According to the question, Profit margin is the difference between the price of a good and the cost to make the good, on a per product basis; and, it is usually expressed as a percentage.