Which Cambridge exam class should I take?

Cambridge Preparation  (PET)

The Preliminary English Test class teaches the English language skills needed to survive in social and work situations in an English speaking environment. 
English Level: GV Sydney (UEC) Lower Intermediate to Intermediate

Cambridge Preparation  (FCE)

The First Certificate in English class  will provide you with a good grounding in grammatical aspects of English and develop your skills in reading, writing, listening and speaking.
English Level: GV Sydney (UEC) Intermediate to Upper Intermediate

Cambridge Preparation (CAE)

The Cambridge Advanced English class is designed for students with a high level of proficiency in English who are already working in English or will be working in English in the near future.
English Level: GV Sydney (UEC) Upper Intermediate to Advanced General English or successful completion of FCE at B pass or higher