Which of the following describes the zone of proximal development that a middle grade teacher should look for when scaffolding learning for students? (Select all that apply)

A. The physical zone around the student that should provide a conducive environment for learning
B. The difference between a learner's ability to perform a task independently versus with guidance
C. The "window of learning" where scaffolding should happen
D. The "window of learning" in which a student is learning independently
E. The zone of learning which best approximates a student's area of interest