A. SELECT dept_id, job_cat, MAX(salary)   FROM employees   WHERE salary > MAX(salary);
B. SELECT dept_id, job_cat, MAX(salary)   FROM employees   GROUP BY dept_id, job_cat;
C. SELECT dept_id, job_cat, MAX(salary)   FROM employees;
D. SELECT dept_id, job_cat, MAX(salary)   FROM employees   GROUP BY dept_id;
E. SELECT dept_id, job_cat, MAX(salary)   FROM employees   GROUP BY dept_id, job_cat, salary;

A. SELECT last_name, 12*salary* commission_pct FROM emp;
B. SELECT last_name, 12*salary* (commission_pct,0) FROM emp;
C. SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;
D. SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;