Which Statement Below Is Correct

Multiple Choice

Which statement below is correct?

A) In order for fusion to be sustained,the critical mass must be exceeded.
B) Fission reactions with light nuclei,such as helium are easily controlled but do not produce as much energy as with heavy nuclei.
C) Breeder reactors are able to convert fissile nuclides into fertile ones,thus "breeding" more fuel.
D) In a pressurized water reactor,cadmium metal usually acts as the moderator.
E) U requires energetic neutrons in order to undergo fission and subsequently produces Pu.