Which action will optimize the query?

Inspect the SELECT query:
Mysql> EXPLAIN SELECT employees. Emp_no, first_name, last_name FROM employees
JOIN title WHERE to_date > ‘2008-10-11’;

2 rows in set (0.00 sec)
Which action will optimize the query?

A.
Add an index to the employees. emp _no column.

B.
Add the keyword STRAIGHT_JOIN.

C.
Add an index on the to_ date column.

D.
Add the FORCE INDEX (PRIMARY) optimizer hint for the employees table.