What is Chu's central idea regarding the United States' role in the global clean energy race?
A
The U.S. should work harder to compete in the development of clean energy
technologies.
B
The U.S. missed the explosion in the solar technology market.
C
The U.S. is no longer an innovator of clean energy technologies.
D
The U.S. must develop the capability to manufacture the energy products it invents.