Identify the correct statements with reference to biogeochemical cycle.

A. It involves both physical and biological processes.

B. It is also referred to as a material cycle or nutrition cycle.

C. Of all the biogeochemical cycles, the nitrogen cycle is the most important as nitrogen makes up 78% of the atmosphere.

D. In biogeochemical cycle the movement of materials is unidirectional.

Choose the correct answer from the options given below: