PLEASE HELP:

Read the scenario.
An ecologist was studying freshwater wetlands across the
southeastern United States. While studying one wetland, the
ecologist noticed that native wetland shrubs and trees were
dying. The ecologist also observed that young shrubs and trees
were stunted in growth and very sparse. At the same time, the
ecologist counted new growth in an invasive reed. The ecologist
wondered why so many native plants were dying.
By reading surveys of the surrounding land, the ecologist
learned that the freshwater wetland bordered a saltmarsh along
the coast. The ecologist also learned that the invasive reed
observed intruding into the wetland was very common in the
nearby saltmarsh. Geological surveys also revealed a gradual
increase in sea level along the coastline and an increase in
salinity in the soil.

Which question most closely relates to the ecologist's
observations and collected data?

A. What is the average age of trees in the freshwater
wetland?
B. How many species of fish live in the freshwater
wetland?
C. Are the wetland trees and shrubs dying due to an
increase in soil salinity?
D. What kinds of wildlife live in the freshwater wetland
compared to the saltmarsh?