A: You can bring a civil suit for defamation.
There are two types of defamation; libel and slander. Libel is a defamatory statement in a permanent form, usually written, e.g. in a newspaper, book, letters, paintings, etc. Slander is a defamatory statement in a transient (non-permanent) form, usually by means of spoken words or gesture (very difficult to prove).
In the case of Facebook postings, it is obviously libel.
The laws governing defamation in Trinidad and Tobago can be found in the Libel and Defamation Act - Chapter 11:16.
Slander- Section 2: No action for defamation shall be maintainable in any Court of justice in Trinidad and Tobago in respect of words spoken, except [in specific clear-cut cases].
Libel - Section 8: If any person maliciously publishes defamatory libel, knowing it to be false, he is liable on conviction to imprisonment for two years and to pay such fine as the Court directs.
Section 9: If any person maliciously publishes any defamatory libel, upon conviction he is liable to pay a fine and to imprisonment for one year.