Which of the following describes an 'effective teacher' in the context of teaching the principles of electricity?
ASomeone who ensures all students memorize the formulas and diagrams perfectly for exams.
BSomeone who strictly follows the prescribed textbook and finishes the syllabus on time.
CSomeone who has a PhD in Electrical Engineering and shares advanced research papers with students.
DSomeone who is skilled at explaining complex concepts in multiple ways using different analogies and models.