In 2016, GDP per capita in Germany was approximately equal to 42000$, using prevailing US/EUR exchange rates. Both countries have similar levels of total factor productivity and capital-labor ratios. Which of the following statements best explains the difference in GDP per capita between Germany and the US?

1. US workers are much more productive, per hour worked, than German workers.
2. The quality of US goods produced is higher than the quality of German goods produced.
3. Either US workers work more hours per year, or there are more workers as a fraction of the total population in the US than in Germany.
4. GDP growth has been much faster over the last two decades in the US than in Germany.