Asedimentary rock containing a fern fossil was found
what does this tell about the area at the time the rock
was formed?

The area must have been on land

Explanation:

Ferns are vascular plants that produces no seeds but reproduce by their spores. They are usually land dwelling plants. Ferns are numerous flowerless and seedless vascular plants having true roots.

Sedimentary rocks usually form as a result of the accumulation of sediments within basins of their deposition. If one encounters fossils of ferns in sedimentary layer, it implies that the sediments must have been brought from land or the area where the sediments were deposited was on land.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

it's c (engineer's do their work with mechanical stuff not on any living being)