Choosing an optional subject is less about “scoring subjects” and more about what you can study consistently for a long time. Start by checking the syllabus of a few optionals and see which one feels understandable and interesting enough to read daily without forcing yourself.
Your background, availability of study material, and access to guidance or answer-writing support also matter. Looking at Previous Year Questions can help you understand the nature of the subject before deciding.
A good optional is simply one you can revise multiple times, practice answer writing in, and stay consistent with throughout your preparation.
