If You Didn't Get a Position That You Really Wanted

If you didn't get a position that you really wanted, which of the following actions should you take?

A) Send a rejection follow-up letter that says you're disappointed but still interested.
B) Make a negative posting about the company on Facebook or Twitter to show how upset you are.
C) Do nothing because contacting the employer again will make you look desperate.
D) Call the employer at least once or twice a week for the next two months to see whether a position is available.