Question

Research into nuclear fusion will likely require a large investment of time and money before it might be used as an energy source.

Which statement best describes the benefits that would make the investment worthwhile?
Fusion requires a large amount of energy and occurs in stars.
Fusion produces large amounts of energy, and the fuel is found on Earth.
Fusion produces no radioactive waste, and the fuel is plentiful.
Fusion requires little energy to begin and would continue through a chain reaction.

Answer 1

"Fusion produces large amounts of energy, and the fuel is found on Earth."

Reason: fusion reactions release very large amounts of energy per mass. Candidate fuels (e.g., deuterium from seawater and tritium bred from lithium) are abundant on Earth, making fusion an attractive long‑term energy source despite the engineering challenges.