Answer:
B- finding new sources of freshwater
Explanation:
To solve the world water crisis we need to conserve water. Finding new sources of water increases the rate of drought, famine and water scarcity in zones. It can also act as a factor of desertification. We need to reduce, reuse and recycle when trying to conserve a resource.
Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Unlike other animals, they lack true tissues and organs, and have no body symmetry.
The shapes of their bodies are adapted for maximal efficiency of water
flow through the central cavity, where it deposits nutrients, and leaves
through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silicon dioxide. All sponges are sessile
aquatic animals. Although there are freshwater species, the great
majority are marine (salt water) species, ranging from tidal zones to
depths exceeding 8,800 m (5.5 mi).