Which of the Following Is an Example of Cooperative Teaching

Which of the following is an example of cooperative teaching?

A) Teachers form teams in which different teachers teach the same lesson to several classes depending on their expertise.
B) Teachers close their classroom doors and teach science the way they want to.
C) Teachers leave science teaching to other teachers better prepared in science.
D) Teachers assign reading and written exercises to their students in preparation for performing demonstrations in their individual classrooms.