Examine the structure of the 'EMPLOYEES' table: EMP_ID NUMBER Primary Key, FIRST NAME VARCHAR2(25), LAST_NAME VARCHAR2(25) Which two statements inserts a row into the table? (Choose two) a. INSERT INTO employees (first_name,last_name, emp_id) VALUES (1000, 'John', 'Smith'); b. INSERT INTO employees VALUES (1000','John',NULL); c. INSERT INTO employees(first_name, last_name) VALUES ('John','Smith); d. INSERT INTO employees (emp_id) VALUES (1000);