How Do We Know That Inquiry Works

How do we know that inquiry works?

A) Research has shown that inquiry teaching produces a somewhat better level of achievement than direct instruction.
B) Research has shown that the achievement gains made as a result of inquiry teaching are longer lasting than the gains made as a result of direct instruction.
C) Research has shown that students who learn in an inquiry environment have better conceptual understandings of the material than students who learned through direct instruction.
D) Studies have shown that elementary science teachers believe students have greater
Achievement in an inquiry setting than in a direct instruction setting.
E) All of the above
F) None of the above