Which INSERT statement is valid?

Examine the structure of the EMPLOYEES table:

Which INSERT statement is valid?

A.
INSERT INTO employees (employee_id, first_name, last_name, hire_date)
VALUES ( 1000, ‘John’, ‘Smith’, ‘01/01/01’);

B.
INSERT INTO employees(employee_id, first_name, last_name, hire_date)
VALUES ( 1000, ‘John’, ‘Smith’, ’01 January 01’);

C.
INSERT INTO employees(employee_id, first_name, last_name, Hire_date)
VALUES ( 1000, ‘John’, ‘Smith’, To_date(‘01/01/01’));

D.
INSERT INTO employees(employee_id, first_name, last_name, hire_date)
VALUES ( 1000, ‘John’, ‘Smith’, 01-Jan-01);

Explanation:
It is the only statement that has a valid date; all other will result in an error.
Answer A is incorrect, syntax error, invalid date format