Which of the following is a type of submersed weed?

Submersed weeds are aquatic plants that grow entirely below the water's surface. The correct answer identifies a specific category of these plants that are rooted in the substrate and do not have leaves that float on the surface. These plants typically have adapted structures that allow them to thrive underwater, supporting their growth and survival in submerged environments.

In contrast, the other types of plants listed do not fit the definition of submersed weeds. Emersed plants grow above the water's surface and are not classified as submersed. Free-floating plants exist on the water surface without anchoring to the bottom, which also excludes them from being categorized as submersed. Epiphytic plants, while they can be associated with aquatic environments, grow on other plants rather than in the substrate itself, further differentiating them from true submersed weeds. This distinction is essential for understanding aquatic plant management and control measures in various water bodies.