This section usually follows the prepared talk and can be on any topic chosen by the examiner. They usually cover at least two topics. However, remember they're there to test your knowledge of the language, not your deep understanding of European Monetary Union or the pros and cons of genetically modified crops.
Check with your class teacher first, but normally if you get a topic that you're not interested in or know little about, tell the examiner; don't try to talk about something you can't really handle (but be prepared to say why you're not interested in politics or the environment when the future of the planet could depend on it and you're the next generation; your actions might decide whether the Earth survives, for example).'It's boring' really isn't enough for A-Level. You could perhaps say that you don't find it very relevant, or that in your opinion, all the power lies with politicians and it doesn't matter what the man in the street thinks, the politicians will just do what they want to.
If you do say you don't want to talk about a particular topic, have another topic ready just in case they ask you what you are interested in talking about. Don't try to think of one on the spot, else you'll end up saying the first thing that comes into your head, like 'the pros and cons of space exploration in the twenty first Century' and then you'll be stuck with it for the next ten minutes!
Generally examiners are fairly lenient about topics but they're not stupid. If you're the fourth candidate in a row who's said that they're not interested in talking about the drug problem in your area and that they'd prefer to talk about violence on television, forget it! You are expected to have some variety of knowledge.
Again, you might be expected to ask the examiner questions in this section even if you asked them in a previous section as well so don't forget.
Look in the question sections for loads of sample questions for different topics.
This might sound really stupid but talk to yourself. Click on one of the questions and try to answer it or try to talk in your head for two minutes on one of the topics. You probably think it's stupid but it really works - it boosts your fluency, your vocab, your confidence and gives you a chance to get used to including certain phrases and expressions and coping with the unexpected if an unusual topic turns up.