The rules of presenting the contents to make them easy are called

Maxims of teaching are the accepted rules of presenting subject matter that make learning easy, such as from known to unknown and simple to complex.

They act as universal guiding principles a teacher follows while proceeding through a lesson.

Methods of teaching (A) are the broad organized ways of instruction like lecture or discussion, not rules of presentation.

Techniques of teaching (C) are specific devices used within a method, such as questioning or illustration.

Teaching strategies (D) are deliberate overall plans chosen to achieve stated objectives.

Standard maxims include known to unknown, simple to complex, concrete to abstract, particular to general, and whole to part.