The cost of producing x ounces of gold from a new gold mine is c = f(x) dollars. (

a) what is the meaning of the derivative f '(x)? what are its units?

a. f '(x) is the average production cost with respect to the number of ounces of gold produced. its units are dollars per ounce.
b. f '(x) is the rate of change of the production cost with respect to the number of ounces of gold produced. its units are dollars per ounce.
c. f '(x) is the total amount of gold produced. its units are ounces.
d. f '(x) is the total production cost. its units are dollars.