Which Statement Is TRUE Concerning Bohr's Model of an Atom

Which statement is TRUE concerning Bohr's model of an atom?

A) The model involved the study of helium.
B) The model led to the understanding that the energy of an electron is quantized.
C) When electrons in an excited state return to the ground state,they absorb light.
D) Bohr's model explains that electrons have a negative charge.
E) The model defines the existence of orbitals.