What environmental process is primarily driven by solar energy?

The correct answer is photosynthesis. This process is fundamentally driven by solar energy, as plants, algae, and some bacteria use sunlight to convert carbon dioxide and water into glucose and oxygen. This transformation is essential for the growth and energy supply of plants, which form the basis of most ecosystems.

Understanding the significance of solar energy in photosynthesis highlights how it supports not just plant life but also the entire food web, since herbivores depend on plants for nutrition, followed by carnivores that rely on herbivores. Additionally, the oxygen produced during photosynthesis is vital for the survival of most living organisms on Earth.

While the water cycle is also influenced by solar energy — as it drives evaporation and other processes — the direct, primary dependence on solar energy in the context of biological functions is more accurately represented by photosynthesis.