The framework for classification of Agroforestry System and practices are:

A. Structure of the system (nature and arrangement of components)
B. Function of the system (role and output of components)
C. Socio-economic seals and management levels of the system
D. All of the above

The correct answer to the question: "The framework for classification of Agroforestry System and practices are:" is "All of the above".