What is the difference between a DBMS and an RDBMS?

(A) A RDBMS uses metadata while a DBMS does not
(B) A DBMS is used for data warehousing
(C) Because a relational database is more complicated than a conventional database, the RDBMS requires much more computing power than the conventional DBMS requires
(D) Because a conventional database is less complicated than a relational database, the DBMS is used more often for transactional databases