Which of the following statements best describes free-floating aquatic plants?

Free-floating aquatic plants are characterized by their ability to float on the water's surface without being anchored to the sediment below. The best description among the options provided indicates that these plants have roots that reach into the water for nutrients; however, it's important to clarify the nature of their growth.

Free-floating plants typically do not have roots that anchor them to the substrate in the way that rooted plants do. Instead, they often possess roots that hang down into the water, which can absorb nutrients and help in buoyancy but do not extend into sediment. This unique structure allows them to benefit from water column nutrients while remaining free to move with the currents.

The other statements are misleading concerning the characteristics of free-floating aquatic plants. They do not grow in sediment as rooted plants do, they thrive best in full light rather than needing underwater exposure, and they cannot thrive in completely shaded environments as they depend on light for photosynthesis.