Answer:
C) The most efficient fusion reactors would use heavier forms of hydrogen.
Step-by-step explanation:
From the information presented to us in the question, the third sentence reveals that heavier forms of hydrogen produces larger amount of energy and most importantly reacts more efficiently when fusion occurs.
In fact, the heavy isotopes of hydrogen—deuterium and tritium—react more efficiently with each other, and, when they do undergo fusion, they yield more energy per reaction than do two hydrogen nuclei.