The Scientific Consensus Concerning Fusion Power Reactors Is That

The scientific consensus concerning fusion power reactors is that

A) such reactors could be commercially feasible, but not until the middle of this century.
B) according to present scientific knowledge, it is impossible to build such reactors.
C) such reactors could be built but they will never be a commercially feasible source of electricity.
D) the first commercial fusion reactors are already under construction and will be ready for use within ten years.
E) such reactors are already a source of commercially feasible electric power.