American Economist Paul Romer Metaphorically Stated, "Economic Growth Springs from Better

American economist Paul Romer metaphorically stated, "Economic growth springs from better recipes, not just from more cooking." What does he mean with this?

A) that rather than working harder, one should work smarter and in new ways
B) that innovations demand development
C) that the key to growth is new knowledge/methods/innovations
D) that the key to growth is to work harder
E) that the key to growth is from more capital in work
F) that the key to growth is having more manpower working harder