Which statement is not correct?

a. In a file-based approach, every application has its own query and access procedures, even if they want to access the same data.

b. SQL is a database language to manage DBMSs without having to write a substantial amount of programming code.

c. SQL is a database language that focuses on how to access and retrieve the data.

d. SQL is a database language that allows different applications to access different subsets of the data necessary for each application.