Question

which of the following can be found in a freshwater ecosystem?
seaweed, seagrass
kelp, algae
cattail, water lilies
mangrove trees

Explanation:

Cattail and Water Lilies are plants that thrive in freshwater environments. Seaweed, Seagrass, Kelp, and Mangrove trees are typically associated with marine or brackish - water ecosystems.

Answer:

Cattail, Water Lilies