Fusion Normally Involves Relatively Light Nuclei Because

Fusion normally involves relatively light nuclei because

A) fusion produces heavier nuclei, and the binding energy per nucleon decreases with atomic number for low atomic numbers.
B) they are the most plentiful.
C) they are easier to ionize and thus to cause their nuclei to coalesce.
D) fusion produces heavier nuclei, and the binding energy per nucleon increases with atomic number for low atomic numbers.