Detailed Answer
(a) The requirement is to identify the language interface
used to establish the structure of database tables. Answer (a) is
correct because DDL is used to define (i.e., determine) the database.
Answer (b) is incorrect because DCL is used to specify
privileges and security rules. Answer (c) is incorrect because
DML provides programmers with a facility to update the database.
Answer (d) is incorrect because DQL is used for ad hoc
queries.