The SQL UPDATE statement is used to modify existing records in a table. In the given statement, there is a subquery that selects the JOB_ID and SALARY of EMPLOYEE_ID 200 and sets these values to the corresponding columns of EMPLOYEE_ID 100.
B . Employee 100 will have SALARY set to the same value as the SALARY of employee 200: This is true because the subquery selects the SALARY of employee 200 and the outer update statement sets this SALARY to employee 100.
C . Employee 100 will have JOB_ID set to the same value as the JOB_ID of employee 200: Similarly, the JOB_ID for employee 100 is updated to match the JOB_ID of employee 200 because of the subquery.
Reference:
Oracle Database SQL Language Reference 12c, particularly the section on the UPDATE statement and subqueries.