What is the primary function of chlorophyll in green plants?

Chlorophyll is a pigment found in the chloroplasts of green plants and is essential for photosynthesis. Its primary function is the absorption of solar energy, specifically capturing light from the sun to convert it into chemical energy. This process enables plants to synthesize their own food using carbon dioxide and water, ultimately producing glucose and oxygen as byproducts. The absorption of solar energy by chlorophyll is crucial for the survival of plants, as it initiates the photosynthetic process, allowing them to grow and thrive.

The other options, while relevant to plant biology, do not directly pertain to the primary function of chlorophyll. Insect protections and growth regulation are important for a plant's overall health but occur through different means and mechanisms separate from chlorophyll's role in light absorption. Similarly, while nutrient uptake is essential for plant nutrition, it does not involve chlorophyll directly in its primary function within the photosynthesis process. Therefore, the correct option focuses on the critical role of chlorophyll in harnessing solar energy for the plant's growth and energy needs.