Which of these is the MOST likely way long-term economic growth takes place?

The correct answer is increased in labor productivity growth. A measure of the amount of output produced by a given amount of inputs in a specific period of time is what we define as productivity. Whereas, an investment in improving the skill level of labor is considered an investment in the human capital. If a government wanted to improve the productivity of its human resources it could expand funding and opportunities for vocational training.