What is the most important precaution to take when using social networking sites like facebook? use discretion monitor friend requests closely use privacy settings have a strong password

Uh, sure having a strong password is always nice. However, a passphrase is far superior. An example would be: My57goatsequals[4log]. Google Edward Snowden, and all your questions will be answered (concerning privacy). Oh, and by the way, use a VPN (Virtual Private Network) whenever possible.

D.is the correct answer to the question

The answer is d) all of the above