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.

Answer 1

"Has been achieved, but is not yet practical."

Explanation: Controlled fusion reactions producing net fusion energy have been demonstrated in experiments (recent milestones include ignition-like results at the NIF and advances in tokamaks), but no fusion power plant has produced grid electricity economically or continuously. Significant technical and engineering challenges remain (sustained net power, materials, fuel handling, cost).