Which of These Is a Fundamental Responsibility of the Teacher

Which of these is a fundamental responsibility of the teacher?

A) The teacher should seek ways to engage all students in the learning process.
B) The teacher should ensure that all students are doing "A" level work.
C) The teacher should see to it that all students are treated the same.
D) The teacher should assess all students in the same way.
E) The teacher should address the same content in the same course every year.