Option C: Energy

C.1.NoS Use theories to explain natural phenomena—energy changes in the world around us result from potential and kinetic energy changes at the molecular level. Energy has both quantity and quality.

Why we study Energy as the option

• Energy synergies better with Chemistry than all other options. This is the most important reason. The link between Energy and the rest of the syllabus is tighter, and studying it reinforces what you have learnt better than the other options.
• Related to above, Energy is easier / higher scoring for most students. (Exception: students with strong Bio & weak Chem.)
• Energy synergizes with Physics and ESS, the same way Biochem (Opt B) synergizes with Bio. (A - Materials and D - Medicine just end up having lots of shallow memorization.) Opt C is renewable energy / solar / global warming, so definitely much more ESS than Biochem.

I have limited capacity to provide support if you choose to study Opt B, but you can certainly choose to study it instead. My belief --- having taught all four options and as a senior examiner for HL P3 --- is that Energy is a better choice for all students including bio students; you have indeed already learnt something about protein and DNA, but you have also learnt your combustion, isotopes, and acidification.