Consider the relational database schema of Figure 3.5. Suppose that all the relations were created by (and hence are owned by) user X, who wants to grant the following privileges to user accounts A, B, C, D, and E:
(a) Account A can retrieve or modify any relation except DEPENDENT and can grant any of these privileges to other users.
(b) Account B can retrieve all the attributes of EMPLOYEE and DEPARTMENT except for SALARY, MGRSSN, and MGRSTARTDATE.
(c) Account C can retrieve or modify WORKS_ON but can only retrieve the FNAME, MINIT, LNAME, SSN attributes of EMPLOYEE and the PNAME, PNUMBER attributes of PROJECT.
(d) Account D can retrieve any attribute of EMPLOYEE or DEPENDENT and can modify DEPENDENT.
(e) Account E can retrieve any attribute of EMPLOYEE but only for EMPLOYEE tuples that have DNO = 3.
(f) Write SQL statements to grant these privileges. Use views were appropriate.