Given:
The equation is

To find:
The properties which is not used from the given options.
Solution:
We have,

Using Multiplication Property of Equality, multiply both sides by 2.

(Distributive Property)
Using Subtraction Property of Equality, subtract 6n from both sides.
From the given options only one property is not used, i.e., Zero Product Property.
Therefore, the correct option is D.