Answer:
All options apply
Step-by-step explanation:
Take for example the following oxidation-reduction reaction:
2 H2 + O2 -> 2 H2O
Hydrogen is oxidized, then its oxidation number increased (from 0 to +1) and lost electrons.
On the other hand, oxygen is reduced, that is, its oxidation number decreased (from 0 to -2) and gain the electrons lost by hydrogen.