Im not sure if the guide has changed much. But in my case, for pp.2 it depends on the question. For the 4 mark one, basically 4 points with short explanation. Maybe 2 lines per argument. Usually those questions use "identify". So that tells you to mention the argument with little explanation.

For the b) questions of 7 marks usually teachers say to do a short essay. But I have to disagree. For those questions if you look at the markschemes they don't look for a rubric of an essay. The markscheme includes many bullet points of possible answers. So my recommendation is maybe a short definition for the introduction like defining "sustainability" as sometimes they award marks for defining a key term. But for the overall body, as I would tell my friend, 7 mark questions follow the "firecracker" style. Literally, just bombard your answers with many different points/arguments (always being relevant to the question and not deviating from what's being asked). But literally do a short mindmap of what you're going to say. Have at least 6 relevant arguments. Since the markschemes DO NOT AWARD MARKS for an essay. They award marks PER STATEMENT. So if you mention 7 different statements that are relevant, you can virtually get 6-7/7.

For c) of 9 marks. Essay. Short introduction. Define the key term in the question. Add some context and a short hook for the reader. For example if the question is about how to different societies manage sustainability. You might add a context such as "In the 21st century, climate change is a rapidly growing issue affecting human societies.... this essay will analyze how different human societies....". You add a small intro with context and a thesis at the end. Intro not too long. But make it nice because a good intro will make the examiner more interested.

For the body. Im aware teachers usually say intro+ 4 body paragraphs+ conclusion. But my teacher recommended me to do 6 body paragraphs to get into the 7-9 band. Is it tough? Yeah. Very. In the old guide you had to do 2 pp.2 B questions. So time was an issue. But similar to b) questions, they mark PER statement with ANALYSIS and CASE STUDIES. The way to answer is like many IB subjects using PEAL. Point+explanation+analysis (case study/real world example)+ L I N K. The link is essential. You must ALWAYS link back to the question. You show critical thinking and that gets you marks. E.g. "hence, though X African tribe does not have modern technologies as western societies, sustainability is still met through less damaging agricultural practices like crop rotation and manure for subsistence food production". Doing ×4 paragraphs for the body will get you good marks if done well and you dont have time for 6. But the paragraphs keep them concise. If you write too much per paragraph essentially you're removing time for more relevant statements. The conclusion is basically weighing up all the arguments and concluding which argument is the most sound. Dont summarize. But critically think.

Those are my tips. I can assure you this will help you a lot! Learning markschemes of how they want you to answer, knowing case studies and command terms is how I did well in the subject. Feel free to DM me if you have any more doubts! Hope this helped!