In Python, 5 golden rules for OOD

Job ID: 35962971

Budget: $2 – $8 USD

There are 5 golden rules in OOD (Object Oriented Design):

Program to Interface Not Implementation
Encapsulate What Varies
Depend on Abstractions, Not Concrete classes
Favor Composition over Inheritance
Strive for Loosely Coupled System
In your own words, in less than 4 lines, please explain which of these is most important and why?