In Mr. Durgan's U.S. history class, students work in teams to explore, research, and present a topic to the class. They can choose from a list of topics or propose a topic to the teacher for approval. Mr. Durgan serves as their guide and mentor for the project. This is an example of
A) The constructivist approach to learning.
B) The jigsaw classroom.
C) Direct instruction.
D) An open education approach.