There are no such topics you should choose. All 3 parts are important. However, it is more likely to get Ethics more than last time.
Perhaps you have to go through all the past year papers and read all requirements of the questions that the examiner could post during the exams so that you could be familiar of the different styles of asking of the examiner but subsequently, you will see that the contents of all the answers are all the same. So just read the past year questions and answers and get your points from there.
Focus on contents of integrated reporting as it could be very important this June 2015 sitting. Read up the AAA (American Accounting Association) model also and Tucker's 5 question approach model. Also read up on the classification of stakeholders.
Internal control (characteristics of a sound internal control system) and business ethics.
Public sector and private/family-owned business sectors could also obtain your attention.
A number of questions will require purely theoretical answers but majority will require application of the case supplied. Therefore, the composition of the questions will be theory - 40% and application - 60%. So make sure you produce a brief plan for longer questions to provide structure and clarity of thought. You should spend your 15 minutes reading time doing this.
Hope this has been useful. All the best of P1! *** bless.