Question

electricity from fusion nuclear energy
is not possible.
accounts for less than 15 percent of current world electricity production.
has been achieved, but is not yet practical.
has been increasing for the past seventy years.

Explanation:

Fusion nuclear energy for electricity generation has been achieved in experimental settings, but challenges like high - energy requirements for containment and control make it not yet practical for large - scale commercial use.

Answer:

has been achieved, but is not yet practical.