Which statements below correctly describes the process of oxidation in a redox reaction. Choose the 2 correct statements.

a
Occurs when atoms gain electrons during bonding.
b
Occurs when the oxidation number of an element decreases in chemical reaction.
c
Occurs when atoms lose electrons during bonding.
d
Occurs when the oxidation number of an element increases in chemical reaction.

c. Occurs when atoms lose electrons during bonding.

d. Occurs when the oxidation number of an element increases in chemical reaction.