[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.