In the context of photosynthesis and the energy that powers it, the process of fusion that keeps our Sun shining begins with which building blocks?

Identify the building blocks: The fusion process begins with hydrogen nuclei (protons) as the primary building blocks. These protons undergo a series of reactions to form helium nuclei, releasing energy in the form of light and heat.

Clarify the incorrect options: Helium atoms are the product of fusion, not the starting material. Carbon dioxide and oxygen molecules are unrelated to the Sun's fusion process; they are involved in Earth's photosynthesis process.