Can you please explain the following question?

(a) Bruce has written a derogatory Facebook post about his ex-girlfriend, Belinda. Parts of the post are untrue, but Bruce wants to exact revenge on Belinda who ended their short relationship by text. Bruce is not really concerned as he has not named Belinda in the post, just his 'ex-girlfriend' and not many people knew about their relationship.

Required:

Belinda finds out about the post. Advise her as to what, if any, legal course of action she may have against Bruce.

(b) Briefly discuss the law in relation to Public Nuisance.