Which of the Following Rules Is Valid When Assigning Oxidation

Which of the following rules is valid when assigning oxidation numbers to atoms?

A) Atoms in their elemental state are assigned an oxidation number of 1.
B) Atoms in the form of molecules have an oxidation number of 1.
C) Hydrogen is assigned a +1 oxidation number when it exists as the hydride ion
D) Atoms in monatomic ions are assigned an oxidation number equal to their charge.
E) Oxygen and hydrogen are usually assigned an oxidation number of zero.