Which of the Following Would Contribute to a Sustained High

Which of the following would contribute to a sustained high rate of economic growth in the long run in an economy?

A) growth in capital per hour worked accompanied by technological change
B) increases in labor force participation rates as workers who are out of the labor force pursue rising wages
C) a shift of workers in the economy from the agricultural sector to the nonagricultural sector
D) an influx of immigrant labor into an economy without any accompanying technological change