Salt marshes, such as the one on the cape hatteras national seashore in north carolina, have a salinity that ranges from 18 to 30 ppt. where does the salt come from? a. salt-tolerant grasses b. migratory birds c. ocean tides d. human intervention

C. Ocean tides is the correct answer.

C. Oceanic tides

Explanation:

Cape Hatteras National Seashore, is an island established on the coasts of Atlantic ocean. The island consists of salt marshes the salinity of which is affected by oceanic currents, water and wind circulation and sea level changes.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.