Which Statement About Antimatter Is Not True

Which statement about antimatter is not true?

A) An antielectron (positron) is identical to an ordinary electron except it has a positive charge.
B) Every ordinary particle has a corresponding antiparticle.
C) When a particle and its antiparticle meet,the result is mutual annihilation that turns all of the mass into energy.
D) Antimatter has been hypothesized to exist but has never actually been detected.