Norway's government nationalized the country's oil resources, and it has been accumulating a massive sovereign wealth fund worth billions of dollars ever since. This sovereign fund is used as a monetary source for government funded national education and healthcare. This is because the wealth generated by nationalized industries:_______

a. always charge high prices and reduce output.
b. is used to serve the interests of oil industry.
c. never return value to citizens of the country.
d. is used to serve the citizens of the country.