Mr Silverman Has Taken Great Pains to Fully Consider the Effectiveness

Mr. Silverman has taken great pains to fully consider the effectiveness of his classroom arrangement. He has made sure to evenly distribute art supplies at different points in the classroom, while still making them easily accessible. He has even made sure that he will be able to see each student. Which of the four basic principles of classroom arrangement has he forgotten?

A) Reduce congestion in high-traffic areas.
B) Make sure he can see each student.
C) Make often-used supplies easily accessible.
D) Make sure arrangement allows each student to see whole-class presentations.