What is the primary function of plant roots?

The primary function of plant roots is to anchor the plant and absorb water and nutrients. Roots serve as the foundational support system of the plant, keeping it securely in the ground and preventing it from being uprooted by wind or other forces. Additionally, roots are crucial for the uptake of water and essential minerals from the soil, which are vital for the plant's growth, development, and metabolic processes.

While some other options relate to important plant functions, they do not pertain to the roots specifically. For instance, absorbing sunlight is the role of leaves, and producing seeds is primarily the function of flowers and reproductive structures. Transporting energy, while essential to plant function, is mostly handled by the vascular tissues (xylem and phloem) and not the roots themselves. Thus, the comprehensive role of roots in anchoring the plant and facilitating nutrient and water absorption makes this option correct.