Which of the Following Environmental Conditions Poses/presents the Strongest Physiological

Multiple Choice

Which of the following environmental conditions poses/presents the strongest physiological challenge for a fish swimming into an estuary from a river?

A) The high water flow would make the fish expend more energy.
B) The low oxygen content would give the fish difficulty in swimming aerobically.
C) The temperature change would stress the fish by denaturing its proteins.
D) The change in water solute content would challenge the osmotic balance of the fish.