How do seagrasses and mangroves increases the health of coral reefs?

Seagrass slow down the water movements and trap the heavy metals and nutrient rich runoff

Mangroves and seagrasses stabilize the sediments, slow down the water movements and trap the heavy metals and nutrient rich runoff, thus improving the water quality for corals and fish communities. They also enhance the biomass of coral reef fishes by providing nursery habitats.

the answer is c i believe