Choose the most appropriate choice with respect to conceptual design.

[A] Conceptual design is a documentation technique. Once the relation schemes are defined one can draw E-R diagrams from the relation schemes for documentation

[B] Conceptual design needs data volumn and processing frequencies to determine the size of the database

[C] Output of any conceptual design is an E-R diagram

[D] Conceptual design involves modeling the data requirements independent of the DBMS, operating system and the hardware.