How has human use of salt marshes changed over time?
a. humans have come to value salt marshes and now seek to preserve and restore them.
b. humans now use drained salt marshes exclusively for agriculture.
c. humans have begun to use salt marshes for landfills.
d. humans have begun to use marsh land for housing and commercial development.

The salt marshes are the wetlands present in the coastal regions, they store the water arising from the floods and the tides in the seas. These marshes have a high ecological importance, and they also help in detoxifying wastes bought by the tides. Many marine organism live and come for the reproduction purposes in these marshes.

Earlier, the importance of the salt mashes  were ignored earlier, but later, humans realised and started protecting them.

hence, the correct answer is option a. Humans have come to value salt marshes and now seek to preserve and restore them.

i'd have to say the answer is probable the second option "the geosphere interacting with the atmosphere"

what exactly is the question lol