In Gamma Decay a Nucleus in an Excited State Decays

In gamma decay a nucleus in an excited state decays to a lower energy state by the emission of a high-energy photon called a gamma ray. Which of the following statements is true?

A) Gamma decay is always slow greater than a ns) .
B) Gamma decay is always fast less than a ns) .
C) Gamma decay is usually fast but can in special cases be slow.
D) Gamma decay is always accompanied by the emission of a neutrino.
E) Gamma decay is always accompanied by the emission of a β particle.