Answer: D. Hydrologist
Step-by-step explanation:
A hydrologist is a scientists who studies the circulation, movement and distribution of surface as well as underground waters.
Such professional studies about the impact of human beings, seasonal changes and natural calamity over the water body.
Hence, the changes occurring in the oceanic water due to seasonal changes is studied by hydrologist. As it involves the physical change in the overall flow of water due to the impact of seasonal change.