Why Do Some Professors Who Teach Difficult Subjects, Such as Math

Multiple Choice

Why do some professors who teach difficult subjects, such as math, struggle with explaining concepts to their students?

A) because the students want to take the "easy road" to learning difficult concepts
B) because the students have shorter attention spans
C) because the professor is an expert and can skip stages in the explanation
D) because the professor can only explain a math concept in complex steps