Hi there, I am also taking the same exams.
For Unit 3B i'm going to revise for The Ontological argument and The problem of evil.
For Unit 4C we did ways of moral decision making. More specifically, we covered medical ethics, Islamic ethics (shariah), the conscience (both religious and non-religious), Divine Command Theory, teleological systems ( Situation Ethics and Utilitarianism), deontological systems (Natural Moral Law and Kantian Ethics), and hybrid ethics (Rule Utilitarianism and Virtue Ethics).
I'm looking forward to participate in this thread.